During the last decade,perovskite solar technologies underwent an impressive development,with power conversion efficiencies reaching 25.5%for single-junction devices and 29.8%for Silicon-Perovskite tandem configuratio...During the last decade,perovskite solar technologies underwent an impressive development,with power conversion efficiencies reaching 25.5%for single-junction devices and 29.8%for Silicon-Perovskite tandem configurations.Even though research mainly focused on improving the efficiency of perovskite photovoltaics(PV),stability and scalability remain fundamental aspects of a mature photovoltaics technology.For n-i-p structure perovskite solar cells,using poly-triaryl(amine)(PTAA)as hole transport layer(HTL)allowed to achieve marked improvements in device stability compared with other common hole conductors.For p-i-n structure,poly-triaryl(amine)is also routinely used as dopant-free hole transport layer,but problems in perovskite film growth,and its limited resistance to stress and imperfect batch-to-batch reproducibility,hamper its use for device upscaling.Following previous computational investigations,in this work,we report the synthesis of two small-molecule organic hole transport layers(BPT-1,2),aiming to solve the above-mentioned issues and allow upscale to the module level.By using BPT-1 and methylammonium-free perovskite,max.Power conversion efficiencies of 17.26%and 15.42%on a small area(0.09 cm^(2))and mini-module size(2.25 cm^(2)),respectively,were obtained,with a better reproducibility than with poly-triaryl(amine).Moreover,BPT-1 was demonstrated to yield more stable devices compared with poly-triaryl(amine)under ISOS-D1,T1,and L1 accelerated life-test protocols,reaching maximum T_(90)values>1000 h on all tests.展开更多
Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite sol...Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite solar cells(PSCs) are synthesized by facile one-step reaction in good yield over 75%. DTF unit as electron donor can enhance the electron donating ability and the fusion of benzenic ring of TPA with DTF unit may lead to reinforced intermolecular interactions in the solid state. In addition,WH-2 and WH-3 exhibit a pyramid shape containing partial planarity and quasi three-dimensionality features, which is also conducive to enhancing the π-π stacking of molecules in the solid state. The above-mentioned structural characteristics make the two HTMs have good hole mobilities. As a result,WH-2 and WH-3 obtained the high intrinsic hole mobilities of 4.69 × 10^(-4)and 2.18 × 10^(-3)cm^(2)V^(-1)s^(-1)respectively. Finally, the power conversion efficiencies(PCEs) of PSCs with WH-2 and WH-3 as cost-effective dopant-free HTMs are 15.39% and 19.22% respectively and the PCE of PSC with WH-3 is on a par with that of PSC with Li-TFSI/t-BP doped Spiro-OMe TAD(19.67%).展开更多
Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable fo...Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable for molecular design of hole-transporting materials in PSCs.We developed an asymmetrically substituted DTP small-molecule(JW12)and a reference compound(JW11).The asymmetrical structure of JW12 leads to different absorption properties and electron distribution.The device in a planar n-i-p architecture using JW12 shows a much higher PCE(18.07%)than that based on JW11(15.46%),which is also better than the device based on spiro-OMe TAD(17.47%).We hope our research can provide a new perspective in molecular design of organic HTMs for perovskite solar cells.展开更多
In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting m...In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting materials(HTMs) is still desired and meaningful. One simple and efficient way to achieve high performance dopant-free HTMs is to synthesize novel non-conjugated side-chain polymers via rational molecular design. In this work, N-(4-methoxyphenyl)-9,9-dimethyl-9H-fluoren-2-amine(FMeNPh) groups are introduced into the poly(N-vinylcarbazole)(PVK) side chains to afford two nonconjugated polymers PVCz-DFMeNPh and PVCz-FMeNPh as dopant-free HTMs in inverted quasi-2D PSCs. Benefited from the flexible properties of polyethylene backbone and excellent optoelectronic natures of FMeNPh side-chain groups, PVCz-DFMeNPh with more FMeNPh units exhibited excellent thermal stability, well-matched energy levels and improved charge mobility as compared to PTAA and PVCzFMeNPh. Moreover, the morphologies investigation of quasi-2D perovskite on PVCz-DFMeNPh shows more compact and homogeneous perovskite films than those on PTAA and PVCz-FMeNPh. As a result,the dopant-free PVCz-DFMeNPh based inverted quasi-2D PSCs deliver power conversion efficiency(PCE) up to 18.44% as well as negligible hysteresis and favorable long-term stability, which represents as excellent performance reported to date for inverted quasi-2D PSCs. The results demonstrate the great potentials of constructing non-conjugated side-chain polymer HTMs based on phenylfluorenamine-func tionalized PVK for the development of high efficient and stable inverted 3D or quasi-2D PSCs.展开更多
Three star-shaped truxene-based small molecules（namely TXH,TXM,TXO） were synthesized,characterized and used as hole-transporting materials（HTMs） for perovskite solar cells（Pv SCs）. The device based on TXO delive...Three star-shaped truxene-based small molecules（namely TXH,TXM,TXO） were synthesized,characterized and used as hole-transporting materials（HTMs） for perovskite solar cells（Pv SCs）. The device based on TXO delivered a respectable power conversion efficiency（PCE） of 7.89% and a high open-circuit voltage（Voc） of 0.97 V,which far exceeded the values of the devices based on other two small molecules. The highest PCE for the device based on TXO is mainly contributed from its lowest series resistance（Rs） value and largest short-circuit current（Jsc） value under the same circumstances. All these results indicate that TXO is a promising HTM candidate for Pv SCs.展开更多
Two electron-rich, solution-processable phenonaphthazine derivatives, 5,12-bis(N-[4,4'-bis-(phenyl) aminophen-4 ''-yl]}-phenonaphthazine (BPZTPA) and 5,12-bis{N-[4,4'-bis(methoxy-phenyl)aminophen-4'...Two electron-rich, solution-processable phenonaphthazine derivatives, 5,12-bis(N-[4,4'-bis-(phenyl) aminophen-4 ''-yl]}-phenonaphthazine (BPZTPA) and 5,12-bis{N-[4,4'-bis(methoxy-phenyl)aminophen-4'-phenonaphthazine (MeO-BPZTPA) have been designed and employed in the fabrication of perovskite solar cells. BPZTPA and MeO-BPZTPA exhibit excellent thermal stabilities, hole mobilities (similar to 10(-4) cm(2)/(V.s)) and suitable HOMO levels (-5.34 and-5.29 eV, respectively) relative to the valence band of the CH3NH3PbI3 and Au work function, showing their potential as alternative hole-transporting materials (HTMs). Meanwhile, the corresponding mesoporous TiO2/CH3NH3PbI3/HTM/Au devices are investigated, and the best power conversion efficiency of 10.36% has been achieved for MeO-BPZTPA without using p-type dopant. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transpor...In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transporting materials(HTMs). Our initial findings demonstrate the donor-dependent methoxy effects. Photovoltaic performance of the HTM with twisted donor highly depends on the methoxy substituent. In contrast, efficiency’s reliance on methoxy is insignificant for the HTM with planar donor. The HTM(M123) featuring the methoxy–substituted carbazole shows a decent power conversion efficiency of 19.33% due to synergistic effects from both planar structure and methoxy. This work gives a guideline to access HTMs reaching both high-performance and good stability.展开更多
Numerous fabrication methods have been developed for high-efficiency perovskite solar cells(PSCs). However, these are limited to spin-coating processes in a glove box and are yet to be commercialized. Therefore, there...Numerous fabrication methods have been developed for high-efficiency perovskite solar cells(PSCs). However, these are limited to spin-coating processes in a glove box and are yet to be commercialized. Therefore, there is a need to develop a controllable and scalable deposition technique that can be carried out under ambient conditions. Even though the doctor-blade coating technique has been widely used to prepare PSCs, it is yet to be applied to high-efficiency PSCs under ambient conditions(RH ~45%, RT ~25 °C). In this study, we conducted blade-coating fabrication of modified high-efficiency PSCs under such conditions. We controlled the substrate temperature to ensure phase transition of perovskite and added dimethyl sulfoxide(DMSO) to the perovskite precursor solution to delay crystallization, which can facilitate the formation of uniform perovskite films by doctor-blade coating. The as-prepared perovskite films had large crystal domains measuring up to 100 μm. Solar cells prepared from these films exhibited a current density that was enhanced from 17.22 to 19.98 m A/cm^2 and an efficiency that was increased from 10.98% to 13.83%. However, the open-circuit voltage was only 0.908 V, probably due to issues with the hole-transporting layer. Subsequently, we replaced poly(3,4-ethylenedioxythiophene) polystyrene sulfonate(PEDOT:PSS) with Ni O x as the hole-transporting material and then prepared higher-quality perovskite films by blade-coating under ambient conditions. The as-prepared perovskite films were preferably orientated and had large crystal domains measuring up to 200 μm;The open-circuit voltage of the resulting PSCs was enhanced from 0.908 to 1.123 V, while the efficiency increased from 13.83% to 15.34%.展开更多
Two hole-transporting materials containing carbazole moieties with TPD- and NPB-like structures, 4,4′-bis [ N- （4-carbazolylphenyl） -N-phenylamino ] biphenyl （ CPB ） and 4,4′-bis [ N- （ 4-carbazolylphenyl ） -...Two hole-transporting materials containing carbazole moieties with TPD- and NPB-like structures, 4,4′-bis [ N- （4-carbazolylphenyl） -N-phenylamino ] biphenyl （ CPB ） and 4,4′-bis [ N- （ 4-carbazolylphenyl ） -N- （ 1-naphthyl ） amino] biphenyl（ CNB）, were synthesized via a modified Ullmann reaction. The resulting compounds were thermally stable with high glass transition temperatures ranging from 145 to 147 ℃ and possessed a good electrochemical reversibility and hole-transporting properties. Typical double-layer device evaluation with the structure ITO/CPB（40 nm）/ Alq3 （60 nm）/LiF/Al demonstrated that they were promising hole-transporting materials with a current efficiency of 5.25 cd/A and a power efficiency of 2.00 lm/W.展开更多
Recent advancements in perovskites’ application as a solar energy harvester have been astonishing. The power conversion efficiency(PCE) of perovskite solar cells(PSCs) is currently reaching parity(>25 percent), an...Recent advancements in perovskites’ application as a solar energy harvester have been astonishing. The power conversion efficiency(PCE) of perovskite solar cells(PSCs) is currently reaching parity(>25 percent), an accomplishment attained over past decades. PSCs are seen as perovskites sandwiched between an electron transporting material(ETM) and a hole transporting material(HTM). As a primary component of PSCs, HTM has been shown to have a considerable effect on solar energy harvesting, carrier extraction and transport, crystallization of perovskite, stability, and price. In PSCs, it is still necessary to use a HTM.While perovskites are capable of conducting holes, they are present in trace amounts, necessitating the use of an HTM layer for efficient charge extraction. In this review, we provide an understanding of the significant forms of HTM accessible(inorganic, polymeric and small molecule-based HTMs), to motivate further research and development of such materials. The identification of additional criteria suggests a significant challenge to high stability and affordability in PSC.展开更多
In recent years the photovoltaic community has witnessed the unprecedented development of perovskite solar cells（PSCs） as they have taken the lead in emergent photovoltaic technologies. The power conversion efficien...In recent years the photovoltaic community has witnessed the unprecedented development of perovskite solar cells（PSCs） as they have taken the lead in emergent photovoltaic technologies. The power conversion efficiency of this new class of solar cells has been increased to a point where they are beginning to compete with more established technologies. Although PSCs have evolved a variety of structures, the use of hole-transporting materials（HTMs） remains indispensable. Here, an overview of the various types of available HTMs is presented. This includes organic and inorganic HTMs and is presented alongside recent progress in associated aspects of PSCs, including device architectures and fabrication techniques to produce high-quality perovskite films. The structure, electrochemistry, and physical properties of a variety of HTMs are discussed, highlighting considerations for those designing new HTMs. Finally, an outlook is presented to provide more concrete direction for the development and optimization of HTMs for highefficiency PSCs.展开更多
Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and...Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.展开更多
Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,spec...Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,specifi cally fl uorenone-triphenylamine(FO-TPA)-x-Cl[x=para,meta,and ortho(p,m,and o)],with diff erent chlorine-substituent positions,as dopant-free HTMs for PSCs.These chlorinated molecules feature a symmetrical donor-acceptor-donor structure and ideal intramolecular charge transfer properties,allowing for self-doping and the establishment of built-in potentials for improving charge extraction.Highly effi cient hole-transfer interfaces are constructed between perovskites and these HTMs by strategi-cally modifying the chlorine substitution.Thus,the chlorinated HTM-derived inverted PSCs exhibited superior effi ciencies and air stabilities.Importantly,the dopant-free HTM FO-TPA-o-Cl not only attains a power conversion effi ciency of 20.82% but also demonstrates exceptional stability,retaining 93.8%of its initial effi ciency even after a 30-day aging test conducted under ambient air conditions in PSCs without encapsulation.These fi ndings underscore the critical role of chlorine-substituent regulation in HTMs in ensuring the formation and maintenance of effi cient and stable PSCs.展开更多
A series of conductive polymers, i.e., poly（3-methylthiophene） （PMT）, poly（thiophene） （PT）, poly（3-bromothiophene） （PBT） and poly（3-chlorothiophene） （PCT）, were prepared via the electrochemical polymer...A series of conductive polymers, i.e., poly（3-methylthiophene） （PMT）, poly（thiophene） （PT）, poly（3-bromothiophene） （PBT） and poly（3-chlorothiophene） （PCT）, were prepared via the electrochemical polymerization process. Subse- quently, their application as hole-transporting materials （HTMs） in CHBNI-I3Pb｜3 perovskite solar cells was explored. It was found that rationally increasing the work function of HTMs proves beneficial in improving the open circuit voltage （Voc） of the devices with an ITO/conductive-polymer/CHBNHBPbIg/C60/BCP/Ag structure. In addition, the higher-Voc devices with a higher-work-function HTM exhibited higher recombination resistances. The highest open circuit voltage of 1.04 V was obtained from devices with PCT, with a work function of -5.4 eV, as the hole-transporting layer. Its power conversion efficiency attained a value of approximately 16.5%, with a high fill factor of 0.764, an appreciable open voltage of 1.01 V and a short circuit current density of 21.4 mA.cm-2. This simple, controllable and low-cost manner of preparing HTMs will be beneficial to the production of large-area perovskite solar cells with a hole-transportin~ laver.展开更多
Organic π-functional molecules are the foundation and basic component of organic optoelectronic devices.For example,for ideal carrier transporting materials,extended π-conjugation and ordered π-πstacking are neces...Organic π-functional molecules are the foundation and basic component of organic optoelectronic devices.For example,for ideal carrier transporting materials,extended π-conjugation and ordered π-πstacking are necessary to enhance the charge mobility and achieve desirable results.As a promising way to convert sunlight into electricity,organometal halide perovskite solar cells（PSCs） have captured a lot of attention due to its predominant merits especially in the aspect of remarkable photovoltaic performance and much potentially low production cost.For conventional planar PSC structure,hole-transporting layer which typically consists of organic π-functional materials plays a key role in suppressing holeelectron pair recombination,promoting charge transporting and ensuring ohmic contact of back electrode.Considering the key roles of HTMs and its soaring progress in recent years,here,we will summarize recent progress in small organic π-functional materials from its diverse functions in PSCs.Besides,aiming to further promote the development of organic π-functional molecules and HTMs,a promising direction toward highly efficient HTMs will also be discussed.展开更多
The development of alternative low-cost and high-performing hole-transporting materials(HTMs) is of great significance for the potential large-scale application of perovskite solar cells(PSCs) in the future.Here,a fac...The development of alternative low-cost and high-performing hole-transporting materials(HTMs) is of great significance for the potential large-scale application of perovskite solar cells(PSCs) in the future.Here,a facilely synthesized solution-processable copper tetra-(2,4-dimethyl-3-pentoxy) phthalocyanine(CuPc-DMP) via only two simple steps,has been incorporated as a hole-transporting material(HTM) in mesoscopic perovskite solar cells(PSCs).The optimized devices based on such a HTM afford a very competitive power conversion efficiency(PCE) of up to 17.1%measured at 100 mW cm^(-2) AM 1.5G irradiation,which is on par with that of the well-known 2,2',7,7'-tetrakis(N'N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene(spiro-OMeTAD)(16.7%) under equivalent conditions.This is,to the best of our knowledge,the highest value reported so far for metal organic complex-based HTMs in PSCs.The advantages of this HTM observed,such as facile synthetic procedure,superior hole transport characteristic,high photovoltaic performance together with the feasibility of tailoring the molecular structure would make solution-processable copper phthalocyanines as a class of promising HTM that can be further explored in PSCs.The present finding highlights the potential application of solution processed metal organic complexes as HTMs for cost-effective and high-performing PSCs.展开更多
Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for t...Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.展开更多
Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largea...Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largearea devices.An impressive certified power conversion efficiency(PCE)of 25.2%has been achieved,demonstrating the excellent potential of PVSCs for future applications.Hole-transporting materials play a key role in improving the device performance of PVSCs by facilitating the extraction of photogenerated holes and their transport from the perovskite layer to the anode.This review provides a brief introduction to PVSCs and summarizes the recent progress in small molecule hole-transporting materials(SM-HTMs)bearing various cores and different4-anisylamino-based end caps.We classify the end caps into N,N-di-4-anisylamino(DAA),4-(N,N-di-4-anisylamino)benzo(DAB),and N3,N6(or N2,N7)-bis(di-4-anisylamino)-9 H-carbazole(3,6-DAC or 2,7-DAC)groups.We also review the core type,end cap position and number,how these affect the overall properties of the SM-HTMs,and the resultant PVSC device performances.Finally,the challenges and perspectives for the future development of SM-HTMs are presented.展开更多
The severe degradation of electrochemical performance for lithium-ion batteries(LIBs)at low temperatures poses a significant challenge to their practical applications.Consequently,extensive efforts have been contribut...The severe degradation of electrochemical performance for lithium-ion batteries(LIBs)at low temperatures poses a significant challenge to their practical applications.Consequently,extensive efforts have been contributed to explore novel anode materials with high electronic conductivity and rapid Li^(+)diffusion kinetics for achieving favorable low-temperature performance of LIBs.Herein,we try to review the recent reports on the synthesis and characterizations of low-temperature anode materials.First,we summarize the underlying mechanisms responsible for the performance degradation of anode materials at subzero temperatures.Second,detailed discussions concerning the key pathways(boosting electronic conductivity,enhancing Li^(+)diffusion kinetics,and inhibiting lithium dendrite)for improving the low-temperature performance of anode materials are presented.Third,several commonly used low-temperature anode materials are briefly introduced.Fourth,recent progress in the engineering of these low-temperature anode materials is summarized in terms of structural design,morphology control,surface&interface modifications,and multiphase materials.Finally,the challenges that remain to be solved in the field of low-temperature anode materials are discussed.This review was organized to offer valuable insights and guidance for next-generation LIBs with excellent low-temperature electrochemical performance.展开更多
The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically sy...The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically synthesize a dicationic salt of X60 termed X60(TFSI)2, and adopt it as an effective and stable "doping" agent to replace the previously used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) for the low-cost organic HTM X60 in PSCs. The incorporation of this dicationic salt significantly increases the hole conductivity of X60 by two orders of magnitude from 10-6 to 10-4 S cm-1. The dramatic enhancement of the conductivity leads to an impressive power conversion efficiency (PCE) of 19.0% measured at 1 sun illumination (100 mW cm-2, AM 1.5 G), which is comparable to that of the device doped with LiTFSI (19.3%) under an identical condition. More strikingly, by replacing LiTFSI, the PSC devices incorporating X60(TFSI)2 also show an excellent long-term durability under ambient atmosphere for 30 days, mainly due to the hydrophobic nature of the X60(TFSI)2 doped HTM layer,which can effectively prevent the moisture destroying the perovskite layer. The present work paves the way for the development of highly efficient, stable, and low-cost HTM for potential commercialization of PSCs.展开更多
基金funding from the Italian Ministry of Economic Development(MISE)in the framework of the Operating Agreement with ENEA for Research on the Electric Systemfrom the Italian Ministry of University and Research(MUR)in the framework of“BEST4U”Project,PON R&I 2014-2020.L.V.,M.S.+2 种基金A.D.C.were supported by the European Union's Horizon 2020 Framework Program for funding Research and Innovation under grant agreement no.764047(ESPResSo)no.691664(UNIQUE,Cofund ERANET Action,MUR GA 775970)no.826013(IMPRESSIVE).C.C.and A.S.acknowledge MIUR Grant—Department of Excellence 2018-2022 and the European Union's Horizon 2020 Framework Program for funding Research and Innovation under grant agreement no.764047(ESPResSo).
文摘During the last decade,perovskite solar technologies underwent an impressive development,with power conversion efficiencies reaching 25.5%for single-junction devices and 29.8%for Silicon-Perovskite tandem configurations.Even though research mainly focused on improving the efficiency of perovskite photovoltaics(PV),stability and scalability remain fundamental aspects of a mature photovoltaics technology.For n-i-p structure perovskite solar cells,using poly-triaryl(amine)(PTAA)as hole transport layer(HTL)allowed to achieve marked improvements in device stability compared with other common hole conductors.For p-i-n structure,poly-triaryl(amine)is also routinely used as dopant-free hole transport layer,but problems in perovskite film growth,and its limited resistance to stress and imperfect batch-to-batch reproducibility,hamper its use for device upscaling.Following previous computational investigations,in this work,we report the synthesis of two small-molecule organic hole transport layers(BPT-1,2),aiming to solve the above-mentioned issues and allow upscale to the module level.By using BPT-1 and methylammonium-free perovskite,max.Power conversion efficiencies of 17.26%and 15.42%on a small area(0.09 cm^(2))and mini-module size(2.25 cm^(2)),respectively,were obtained,with a better reproducibility than with poly-triaryl(amine).Moreover,BPT-1 was demonstrated to yield more stable devices compared with poly-triaryl(amine)under ISOS-D1,T1,and L1 accelerated life-test protocols,reaching maximum T_(90)values>1000 h on all tests.
基金the Sichuan Science and Technology Program (2019YJ0162)the National Natural Science Foundation of China (21402023, 51773027)the National Key R@D Program of China (2017YFB0702802) for financial support。
文摘Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite solar cells(PSCs) are synthesized by facile one-step reaction in good yield over 75%. DTF unit as electron donor can enhance the electron donating ability and the fusion of benzenic ring of TPA with DTF unit may lead to reinforced intermolecular interactions in the solid state. In addition,WH-2 and WH-3 exhibit a pyramid shape containing partial planarity and quasi three-dimensionality features, which is also conducive to enhancing the π-π stacking of molecules in the solid state. The above-mentioned structural characteristics make the two HTMs have good hole mobilities. As a result,WH-2 and WH-3 obtained the high intrinsic hole mobilities of 4.69 × 10^(-4)and 2.18 × 10^(-3)cm^(2)V^(-1)s^(-1)respectively. Finally, the power conversion efficiencies(PCEs) of PSCs with WH-2 and WH-3 as cost-effective dopant-free HTMs are 15.39% and 19.22% respectively and the PCE of PSC with WH-3 is on a par with that of PSC with Li-TFSI/t-BP doped Spiro-OMe TAD(19.67%).
基金supported by the Scientific Research Project of Tianjin Municipal Education Committee(2017KJ261)。
文摘Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable for molecular design of hole-transporting materials in PSCs.We developed an asymmetrically substituted DTP small-molecule(JW12)and a reference compound(JW11).The asymmetrical structure of JW12 leads to different absorption properties and electron distribution.The device in a planar n-i-p architecture using JW12 shows a much higher PCE(18.07%)than that based on JW11(15.46%),which is also better than the device based on spiro-OMe TAD(17.47%).We hope our research can provide a new perspective in molecular design of organic HTMs for perovskite solar cells.
基金financially supported by the National Key Research and Development Program of China (2018YFB0406704)the National Natural Science Foundation of China (61974066, 61725502, 61634001)+3 种基金the Major Research Plan of the National Natural Science Foundation of China (91733302)the fund for Talented of Nanjing Tech University (201983)the Major Program of Natural Science Research of Jiangsu Higher Education Institutions of China (18KJA510002)the Synergetic Innovation Center for Organic Electronics and Information Displays。
文摘In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting materials(HTMs) is still desired and meaningful. One simple and efficient way to achieve high performance dopant-free HTMs is to synthesize novel non-conjugated side-chain polymers via rational molecular design. In this work, N-(4-methoxyphenyl)-9,9-dimethyl-9H-fluoren-2-amine(FMeNPh) groups are introduced into the poly(N-vinylcarbazole)(PVK) side chains to afford two nonconjugated polymers PVCz-DFMeNPh and PVCz-FMeNPh as dopant-free HTMs in inverted quasi-2D PSCs. Benefited from the flexible properties of polyethylene backbone and excellent optoelectronic natures of FMeNPh side-chain groups, PVCz-DFMeNPh with more FMeNPh units exhibited excellent thermal stability, well-matched energy levels and improved charge mobility as compared to PTAA and PVCzFMeNPh. Moreover, the morphologies investigation of quasi-2D perovskite on PVCz-DFMeNPh shows more compact and homogeneous perovskite films than those on PTAA and PVCz-FMeNPh. As a result,the dopant-free PVCz-DFMeNPh based inverted quasi-2D PSCs deliver power conversion efficiency(PCE) up to 18.44% as well as negligible hysteresis and favorable long-term stability, which represents as excellent performance reported to date for inverted quasi-2D PSCs. The results demonstrate the great potentials of constructing non-conjugated side-chain polymer HTMs based on phenylfluorenamine-func tionalized PVK for the development of high efficient and stable inverted 3D or quasi-2D PSCs.
基金supported by the National Natural Science Foundation of China(Nos.61325026,51503209)the Natural Science Foundation of Fujian Province(No.2015H0050)
文摘Three star-shaped truxene-based small molecules（namely TXH,TXM,TXO） were synthesized,characterized and used as hole-transporting materials（HTMs） for perovskite solar cells（Pv SCs）. The device based on TXO delivered a respectable power conversion efficiency（PCE） of 7.89% and a high open-circuit voltage（Voc） of 0.97 V,which far exceeded the values of the devices based on other two small molecules. The highest PCE for the device based on TXO is mainly contributed from its lowest series resistance（Rs） value and largest short-circuit current（Jsc） value under the same circumstances. All these results indicate that TXO is a promising HTM candidate for Pv SCs.
基金the financial support from National High-tech R&D Program(863 Program)(2015AA033402)the Science and Technology Planning Project of Tianjin Province,China(No.14TXGCCX00017)+1 种基金Tianjin science and technology plan projects(13ZCZDGX00900)the National Natural Science Foundation of China(No.11474333)
文摘Two electron-rich, solution-processable phenonaphthazine derivatives, 5,12-bis(N-[4,4'-bis-(phenyl) aminophen-4 ''-yl]}-phenonaphthazine (BPZTPA) and 5,12-bis{N-[4,4'-bis(methoxy-phenyl)aminophen-4'-phenonaphthazine (MeO-BPZTPA) have been designed and employed in the fabrication of perovskite solar cells. BPZTPA and MeO-BPZTPA exhibit excellent thermal stabilities, hole mobilities (similar to 10(-4) cm(2)/(V.s)) and suitable HOMO levels (-5.34 and-5.29 eV, respectively) relative to the valence band of the CH3NH3PbI3 and Au work function, showing their potential as alternative hole-transporting materials (HTMs). Meanwhile, the corresponding mesoporous TiO2/CH3NH3PbI3/HTM/Au devices are investigated, and the best power conversion efficiency of 10.36% has been achieved for MeO-BPZTPA without using p-type dopant. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金the financial support from the National Science Foundation of China (No.21373007, 21671148)the Tianjin Natural Science Foundation (18JCYBJC21600, 18JCZDJC97000)+1 种基金111 project (B12015)Training Project of Innovation Team of Colleges and Universities in Tianjin (TD13-5020)。
文摘In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transporting materials(HTMs). Our initial findings demonstrate the donor-dependent methoxy effects. Photovoltaic performance of the HTM with twisted donor highly depends on the methoxy substituent. In contrast, efficiency’s reliance on methoxy is insignificant for the HTM with planar donor. The HTM(M123) featuring the methoxy–substituted carbazole shows a decent power conversion efficiency of 19.33% due to synergistic effects from both planar structure and methoxy. This work gives a guideline to access HTMs reaching both high-performance and good stability.
基金supported by the National Key Research and Development Project funding from the Ministry of Science and Technology of China (Grants Nos. 2016YFA0202400 and 2016YFA0202404)the Peacock Team Project funding from Shenzhen Science and Technology Innovation Committee (Grant No. KQTD2015033110182370)+1 种基金the Fundamental Research (Discipline Arrangement) Project funding from Shenzhen Science and Technology Innovation Committee (Grant No. JCYJ20170412154554048)the National Natural Science Foundation of China (Grant No. 51473139)
文摘Numerous fabrication methods have been developed for high-efficiency perovskite solar cells(PSCs). However, these are limited to spin-coating processes in a glove box and are yet to be commercialized. Therefore, there is a need to develop a controllable and scalable deposition technique that can be carried out under ambient conditions. Even though the doctor-blade coating technique has been widely used to prepare PSCs, it is yet to be applied to high-efficiency PSCs under ambient conditions(RH ~45%, RT ~25 °C). In this study, we conducted blade-coating fabrication of modified high-efficiency PSCs under such conditions. We controlled the substrate temperature to ensure phase transition of perovskite and added dimethyl sulfoxide(DMSO) to the perovskite precursor solution to delay crystallization, which can facilitate the formation of uniform perovskite films by doctor-blade coating. The as-prepared perovskite films had large crystal domains measuring up to 100 μm. Solar cells prepared from these films exhibited a current density that was enhanced from 17.22 to 19.98 m A/cm^2 and an efficiency that was increased from 10.98% to 13.83%. However, the open-circuit voltage was only 0.908 V, probably due to issues with the hole-transporting layer. Subsequently, we replaced poly(3,4-ethylenedioxythiophene) polystyrene sulfonate(PEDOT:PSS) with Ni O x as the hole-transporting material and then prepared higher-quality perovskite films by blade-coating under ambient conditions. The as-prepared perovskite films were preferably orientated and had large crystal domains measuring up to 200 μm;The open-circuit voltage of the resulting PSCs was enhanced from 0.908 to 1.123 V, while the efficiency increased from 13.83% to 15.34%.
文摘Two hole-transporting materials containing carbazole moieties with TPD- and NPB-like structures, 4,4′-bis [ N- （4-carbazolylphenyl） -N-phenylamino ] biphenyl （ CPB ） and 4,4′-bis [ N- （ 4-carbazolylphenyl ） -N- （ 1-naphthyl ） amino] biphenyl（ CNB）, were synthesized via a modified Ullmann reaction. The resulting compounds were thermally stable with high glass transition temperatures ranging from 145 to 147 ℃ and possessed a good electrochemical reversibility and hole-transporting properties. Typical double-layer device evaluation with the structure ITO/CPB（40 nm）/ Alq3 （60 nm）/LiF/Al demonstrated that they were promising hole-transporting materials with a current efficiency of 5.25 cd/A and a power efficiency of 2.00 lm/W.
文摘Recent advancements in perovskites’ application as a solar energy harvester have been astonishing. The power conversion efficiency(PCE) of perovskite solar cells(PSCs) is currently reaching parity(>25 percent), an accomplishment attained over past decades. PSCs are seen as perovskites sandwiched between an electron transporting material(ETM) and a hole transporting material(HTM). As a primary component of PSCs, HTM has been shown to have a considerable effect on solar energy harvesting, carrier extraction and transport, crystallization of perovskite, stability, and price. In PSCs, it is still necessary to use a HTM.While perovskites are capable of conducting holes, they are present in trace amounts, necessitating the use of an HTM layer for efficient charge extraction. In this review, we provide an understanding of the significant forms of HTM accessible(inorganic, polymeric and small molecule-based HTMs), to motivate further research and development of such materials. The identification of additional criteria suggests a significant challenge to high stability and affordability in PSC.
基金financial support from the Natural Science Foundation of China (grant numbers: 51661135021, 21606039, 91233201, and 21276044)
文摘In recent years the photovoltaic community has witnessed the unprecedented development of perovskite solar cells（PSCs） as they have taken the lead in emergent photovoltaic technologies. The power conversion efficiency of this new class of solar cells has been increased to a point where they are beginning to compete with more established technologies. Although PSCs have evolved a variety of structures, the use of hole-transporting materials（HTMs） remains indispensable. Here, an overview of the various types of available HTMs is presented. This includes organic and inorganic HTMs and is presented alongside recent progress in associated aspects of PSCs, including device architectures and fabrication techniques to produce high-quality perovskite films. The structure, electrochemistry, and physical properties of a variety of HTMs are discussed, highlighting considerations for those designing new HTMs. Finally, an outlook is presented to provide more concrete direction for the development and optimization of HTMs for highefficiency PSCs.
基金the National Natural Science Foundation of China(22065038)the Key Project of Natural Science Foundation of Yunnan(KC10110419)+4 种基金the High-Level Talents Introduction in Yunnan Province(C619300A010)the Fund for Excellent Young Scholars of Yunnan(K264202006820)the Program for Excellent Young Talents of Yunnan University and Major Science(C176220200)the International Joint Research Center for Advanced Energy Materials of Yunnan Province(202003AE140001)the Technology Project of Precious Metal Materials Genetic Engineering in Yunnan Province(No.2019Z E001-1202002AB080001)for financial support。
文摘Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.
基金This study was supported by the National Nat-ural Science Foundation of China(No.22379105)the Natural Sci-ence Foundation of Shanxi Province(Nos.20210302123110 and 202303021211059)the Open Fund Project of Ningxia Sinostar Display Material Co.,Ltd.
文摘Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,specifi cally fl uorenone-triphenylamine(FO-TPA)-x-Cl[x=para,meta,and ortho(p,m,and o)],with diff erent chlorine-substituent positions,as dopant-free HTMs for PSCs.These chlorinated molecules feature a symmetrical donor-acceptor-donor structure and ideal intramolecular charge transfer properties,allowing for self-doping and the establishment of built-in potentials for improving charge extraction.Highly effi cient hole-transfer interfaces are constructed between perovskites and these HTMs by strategi-cally modifying the chlorine substitution.Thus,the chlorinated HTM-derived inverted PSCs exhibited superior effi ciencies and air stabilities.Importantly,the dopant-free HTM FO-TPA-o-Cl not only attains a power conversion effi ciency of 20.82% but also demonstrates exceptional stability,retaining 93.8%of its initial effi ciency even after a 30-day aging test conducted under ambient air conditions in PSCs without encapsulation.These fi ndings underscore the critical role of chlorine-substituent regulation in HTMs in ensuring the formation and maintenance of effi cient and stable PSCs.
文摘A series of conductive polymers, i.e., poly（3-methylthiophene） （PMT）, poly（thiophene） （PT）, poly（3-bromothiophene） （PBT） and poly（3-chlorothiophene） （PCT）, were prepared via the electrochemical polymerization process. Subse- quently, their application as hole-transporting materials （HTMs） in CHBNI-I3Pb｜3 perovskite solar cells was explored. It was found that rationally increasing the work function of HTMs proves beneficial in improving the open circuit voltage （Voc） of the devices with an ITO/conductive-polymer/CHBNHBPbIg/C60/BCP/Ag structure. In addition, the higher-Voc devices with a higher-work-function HTM exhibited higher recombination resistances. The highest open circuit voltage of 1.04 V was obtained from devices with PCT, with a work function of -5.4 eV, as the hole-transporting layer. Its power conversion efficiency attained a value of approximately 16.5%, with a high fill factor of 0.764, an appreciable open voltage of 1.01 V and a short circuit current density of 21.4 mA.cm-2. This simple, controllable and low-cost manner of preparing HTMs will be beneficial to the production of large-area perovskite solar cells with a hole-transportin~ laver.
基金the financial support from the National Natural Science Foundation of China(Nos.21572152 and 61575136)funded by Collaborative Innovation Center (CIC) of Suzhou Nano Science and Technologyby the Priority Academic Program Development of the Jiangsu Higher Education Institutions (PAPD)
文摘Organic π-functional molecules are the foundation and basic component of organic optoelectronic devices.For example,for ideal carrier transporting materials,extended π-conjugation and ordered π-πstacking are necessary to enhance the charge mobility and achieve desirable results.As a promising way to convert sunlight into electricity,organometal halide perovskite solar cells（PSCs） have captured a lot of attention due to its predominant merits especially in the aspect of remarkable photovoltaic performance and much potentially low production cost.For conventional planar PSC structure,hole-transporting layer which typically consists of organic π-functional materials plays a key role in suppressing holeelectron pair recombination,promoting charge transporting and ensuring ohmic contact of back electrode.Considering the key roles of HTMs and its soaring progress in recent years,here,we will summarize recent progress in small organic π-functional materials from its diverse functions in PSCs.Besides,aiming to further promote the development of organic π-functional molecules and HTMs,a promising direction toward highly efficient HTMs will also be discussed.
基金supported by the National Natural Science Foundation of China(21606039,21120102036,91233201)the National Basic Research Program of China(2014CB239402)+2 种基金the Swedish Energy Agencythe KnutAlice Wallenberg Foundatioa
文摘The development of alternative low-cost and high-performing hole-transporting materials(HTMs) is of great significance for the potential large-scale application of perovskite solar cells(PSCs) in the future.Here,a facilely synthesized solution-processable copper tetra-(2,4-dimethyl-3-pentoxy) phthalocyanine(CuPc-DMP) via only two simple steps,has been incorporated as a hole-transporting material(HTM) in mesoscopic perovskite solar cells(PSCs).The optimized devices based on such a HTM afford a very competitive power conversion efficiency(PCE) of up to 17.1%measured at 100 mW cm^(-2) AM 1.5G irradiation,which is on par with that of the well-known 2,2',7,7'-tetrakis(N'N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene(spiro-OMeTAD)(16.7%) under equivalent conditions.This is,to the best of our knowledge,the highest value reported so far for metal organic complex-based HTMs in PSCs.The advantages of this HTM observed,such as facile synthetic procedure,superior hole transport characteristic,high photovoltaic performance together with the feasibility of tailoring the molecular structure would make solution-processable copper phthalocyanines as a class of promising HTM that can be further explored in PSCs.The present finding highlights the potential application of solution processed metal organic complexes as HTMs for cost-effective and high-performing PSCs.
基金supported in part by STI 2030-Major Projects under Grant 2022ZD0209200sponsored by Tsinghua-Toyota Joint Research Fund+12 种基金in part by National Natural Science Foundation of China under Grant 62374099, Grant 62022047, Grant U20A20168, Grant 51861145202, Grant 51821003, and Grant 62175219in part by the National Key R&D Program under Grant 2016YFA0200400in part by Beijing Natural Science-Xiaomi Innovation Joint Fund Grant L233009in part supported by Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies (JIAOT KF202204)in part by the Daikin-Tsinghua Union Programin part sponsored by CIE-Tencent Robotics X Rhino-Bird Focused Research Programin part by the Guoqiang Institute, Tsinghua Universityin part by the Research Fund from Beijing Innovation Center for Future Chipin part by Shanxi “1331 Project” Key Subjects Constructionin part by the Youth Innovation Promotion Association of Chinese Academy of Sciences (2019120)the opening fund of Key Laboratory of Science and Technology on Silicon Devices, Chinese Academy of Sciencesin part by the project of MOE Innovation Platformin part by the State Key Laboratory of Integrated Chips and Systems
文摘Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.
基金the National Natural Science Foundation of China(NSFC,21825502)the Foundation of State Key Laboratory of Polymer Materials Engineering(SKLPME 2017-2-04)the Fundamental Research Funds for the Central Universities。
文摘Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largearea devices.An impressive certified power conversion efficiency(PCE)of 25.2%has been achieved,demonstrating the excellent potential of PVSCs for future applications.Hole-transporting materials play a key role in improving the device performance of PVSCs by facilitating the extraction of photogenerated holes and their transport from the perovskite layer to the anode.This review provides a brief introduction to PVSCs and summarizes the recent progress in small molecule hole-transporting materials(SM-HTMs)bearing various cores and different4-anisylamino-based end caps.We classify the end caps into N,N-di-4-anisylamino(DAA),4-(N,N-di-4-anisylamino)benzo(DAB),and N3,N6(or N2,N7)-bis(di-4-anisylamino)-9 H-carbazole(3,6-DAC or 2,7-DAC)groups.We also review the core type,end cap position and number,how these affect the overall properties of the SM-HTMs,and the resultant PVSC device performances.Finally,the challenges and perspectives for the future development of SM-HTMs are presented.
基金supported by the National Key Research and Development Program of China(No.2019YFA0705601)the National Natural Science Foundation of China(No.U23A20122,52101267)the Key Science and Technology Special Project of Henan Province(No.201111311400).
文摘The severe degradation of electrochemical performance for lithium-ion batteries(LIBs)at low temperatures poses a significant challenge to their practical applications.Consequently,extensive efforts have been contributed to explore novel anode materials with high electronic conductivity and rapid Li^(+)diffusion kinetics for achieving favorable low-temperature performance of LIBs.Herein,we try to review the recent reports on the synthesis and characterizations of low-temperature anode materials.First,we summarize the underlying mechanisms responsible for the performance degradation of anode materials at subzero temperatures.Second,detailed discussions concerning the key pathways(boosting electronic conductivity,enhancing Li^(+)diffusion kinetics,and inhibiting lithium dendrite)for improving the low-temperature performance of anode materials are presented.Third,several commonly used low-temperature anode materials are briefly introduced.Fourth,recent progress in the engineering of these low-temperature anode materials is summarized in terms of structural design,morphology control,surface&interface modifications,and multiphase materials.Finally,the challenges that remain to be solved in the field of low-temperature anode materials are discussed.This review was organized to offer valuable insights and guidance for next-generation LIBs with excellent low-temperature electrochemical performance.
基金supported by the National Natural Science Foundation of China (21606039, 51661135021, 91233201)the Fundamental Research Funds for the Central UniversitiesSwedish Foundation for Strategic Research (SSF),the Swedish Energy Agency, and the Knut and Alice Wallenberg Foundation
文摘The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically synthesize a dicationic salt of X60 termed X60(TFSI)2, and adopt it as an effective and stable "doping" agent to replace the previously used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) for the low-cost organic HTM X60 in PSCs. The incorporation of this dicationic salt significantly increases the hole conductivity of X60 by two orders of magnitude from 10-6 to 10-4 S cm-1. The dramatic enhancement of the conductivity leads to an impressive power conversion efficiency (PCE) of 19.0% measured at 1 sun illumination (100 mW cm-2, AM 1.5 G), which is comparable to that of the device doped with LiTFSI (19.3%) under an identical condition. More strikingly, by replacing LiTFSI, the PSC devices incorporating X60(TFSI)2 also show an excellent long-term durability under ambient atmosphere for 30 days, mainly due to the hydrophobic nature of the X60(TFSI)2 doped HTM layer,which can effectively prevent the moisture destroying the perovskite layer. The present work paves the way for the development of highly efficient, stable, and low-cost HTM for potential commercialization of PSCs.
