Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of f...Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of flexible Sb_(2)Se_(3) photovoltaic devices is temporarily limited by the complicated intrinsic defects and the undesirable contact interfaces.Herein,a high-quality Sb_(2)Se_(3) absorber layer with large crystal grains and benign [hkl] growth orientation can be first prepared on a Mo foil substrate.Then NaF intermediate layer is introduced between Mo and Sb_(2)Se_(3),which can further optimize the growth of Sb_(2)Se_(3)thin film.Moreover,positive Na ion diffusion enables it to dramatically lower barrier height at the back contact interface and passivate harmful defects at both bulk and heterojunction.As a result,the champion substrate structured Mo-foil/Mo/NaF/Sb_(2)Se_(3)/CdS/ITO/Ag flexible thin-film solar cell delivers an obviously higher efficiency of 8.03% and a record open-circuit voltage(V_(OC)) of 0.492 V.This flexible Sb_(2)Se_(3) device also exhibits excellent stability and flexibility to stand large bending radius and multiple bending times,as well as superior weak light photo-response with derived efficiency of 12.60%.This work presents an effective strategy to enhance the flexible Sb_(2)Se_(3) device performance and expand its potential photovoltaic applications.展开更多
Antimony selenide(Sb_(2)Se_(3))is a potential photovoltaic(PV)material for next-generation solar cells and has achieved great development in the last several years.The properties of Sb_(2)Se_(3)absorber and back conta...Antimony selenide(Sb_(2)Se_(3))is a potential photovoltaic(PV)material for next-generation solar cells and has achieved great development in the last several years.The properties of Sb_(2)Se_(3)absorber and back contact influence the PV performances of Sb_(2)Se_(3)solar cells.Hence,optimization of back contact characteristics and absorber orientation are crucial steps in raising the power conversion efficiency(PCE)of Sb_(2)Se_(3)solar cells.In this work,MoO2was introduced as an intermediate layer(IL)in Sb_(2)Se_(3)solar cells,and comparative investigations were conducted.The growth of(211)-oriented Sb_(2)Se_(3)with large grains was facilitated by introducing the MoO2IL with suitable thickness.The MoO2IL substantially lowered the back contact barrier and prevented the formation of voids at the back contact,which reduced the thickness of the MoSe2interface layer,inhibited carrier recombination,and minimized bulk and interfacial defects in devices.Subsequently,significant optimization enhanced the open-circuit voltage(VOC)of solar cells from 0.481 V to 0.487 V,short-circuit current density(JSC)from 23.81 m A/cm^(2)to 29.29 m A/cm^(2),and fill factor from 50.28%to 57.10%,which boosted the PCE from 5.75%to 8.14%.展开更多
Photoelectrochemical(PEC) cells involved with semiconductor electrodes can simultaneously absorb solar energy and perform chemical reactions, which are considered as an attractive strategy to produce renewable and cle...Photoelectrochemical(PEC) cells involved with semiconductor electrodes can simultaneously absorb solar energy and perform chemical reactions, which are considered as an attractive strategy to produce renewable and clean hydrogen energy. Sb_(2)Se_(3) has been widely investigated in constructing PEC photocathodes benefitting of its low toxicity, suitable band gap, superior optoelectronic properties, and outstanding photocorrosion stability. We first present a brief overview of basic concepts and principles of PEC water splitting as well as a comparison between Sb_(2)Se_(3) and other numerous candidates. Then the material characteristics and preparation methods of Sb_(2)Se_(3) are introduced. The development of Sb_(2)Se_(3)-based photocathodes in PEC water splitting with various architectures and engineering efforts(i.e., absorber engineering, interfaces engineering, co-catalyst engineering and tandem engineering) to improve solar-to-hydrogen(STH) efficiency are highlighted. Finally, we debate the possible future directions to further explore the researching fields of Sb_(2)Se_(3)-based photocathodes with a strongly positive outlook in PEC processed solar hydrogen production.展开更多
In recent years,Cu_(2)ZnSnS_(4)(CZTS)semiconductor materials have received intensive attention in the field of thin-film solar cells owing to its non-toxic and low-cost elements.In this work,double-pressure sputtering...In recent years,Cu_(2)ZnSnS_(4)(CZTS)semiconductor materials have received intensive attention in the field of thin-film solar cells owing to its non-toxic and low-cost elements.In this work,double-pressure sputtering technology is applied to obtain highly efficient and ultra-thin(-450 nm)pure Cu_(2)ZnSnS_(4)(CZTS)solar cell.Using mixed materials with sulfides and copper powder as a quaternary target via spark plasma sintering(SPS)method and adopting double-layer sputtering(high+low pressure),a highly adhesive and large-grained CZTS thin film is achieved.As a result,the damage to the surface of Mo contact is decreased so that the reflectivity of incident light can be improved.Moreover,the composition of CZTS film was more uniform and the secondary phase separation at the Mo interface was reduced.Therefore,the interface defect state and deep level defect density in corresponding device with double-pressure is reduced and the ratio of depletion thickness to absorption layer thickness can reached to 0.58,which promoted the collection of photogenerated carriers.Finally,an efficiency of 9.3%for ultra-thin(~450 nm)CZTS film solar cell is obtained.展开更多
Kesterite Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)has attracted considerable attention as a non-toxic and earthabundant solar cell material.During selenization of CZTSSe film at high temperature,the reaction between CZTSSe and Mo...Kesterite Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)has attracted considerable attention as a non-toxic and earthabundant solar cell material.During selenization of CZTSSe film at high temperature,the reaction between CZTSSe and Mo is one of the main reasons that result in unfavorable absorber and interface quality,which leads to large open circuit voltage deficit(VOC-def)and low fill factor(FF).Herein,a WO_(3)intermediate layer introduced at the back interface can effectually inhibit the unfavorable interface reaction between absorber and back electrode in the preliminary selenization progress;thus high-quality crystals are obtained.Through this back interface engineering,the traditional problems of phase segregation,voids in the absorber and over thick Mo(S,Se)_(2)at the back interface can be well solved,which greatly lessens the recombination in the bulk and at the interface.The increased minority carrier diffusion length,decreased barrier height at back interface contact and reduced deep acceptor defects give rise to systematic improvement in VOCand FF,finally a 12.66%conversion efficiency for CZTSSe solar cell has been achieved.This work provides a simple way to fabricate highly efficient solar cells and promotes a deeper understanding of the function of intermediate layer at back interface in kesterite-based solar cells.展开更多
Al2O3 films were prepared using electron beam evaporation at room temperature. The samples were irradiated with oxygen plasma under different energy. The variations in average surface defect density and root mean squa...Al2O3 films were prepared using electron beam evaporation at room temperature. The samples were irradiated with oxygen plasma under different energy. The variations in average surface defect density and root mean square (RMS) surface roughness were characterized using an optical microscope and an atomic force microscope. Surface average defect density increased after plasma treatment. The RMS surface roughness of the samples decreased from 1.92 nm to 1.26 nm because of surface atom restructuring after oxygen plasma conditioning. A 355 nm laser-induced damage experiment indicated that the as-grown sample with the lowest defect density exhibited a higher laser-induced damage threshold (1.12 J/cm2) than the other treated samples. Laser-induced damage images revealed that defect is one of the key factors that affect laser-induced damage on Al2O3 films.展开更多
Antimony selenide(Sb_(2)Se_(3))is a promising candidate for photodetector applications boasting unique material benefits and remarkable optoelectronic properties.Achieving high-performance self-powered Sb_(2)Se_(3)pho...Antimony selenide(Sb_(2)Se_(3))is a promising candidate for photodetector applications boasting unique material benefits and remarkable optoelectronic properties.Achieving high-performance self-powered Sb_(2)Se_(3)photodetector through a synergistic regulation of absorber layer and heterojunction interface demonstrates great potential and needs essential investigation.In this study,an effective two-step thermodynamic/kinetic deposition technique containing sputtered and selenized Sb precursor is implemented to induce self-assembled growth of Sb_(2)Se_(3)light absorbing thin film with large crystal grains and desirable[hk1]orientation,presenting considerable thin-film photodetector performance.Furthermore,aluminum(Al^(3+))cation dopant is introduced to modify the optoelectronic properties of CdS buffer layer,and further optimize the Sb_(2)Se_(3)/CdS(Al)heterojunction interface quality.Thanks to the suppressed carrier recombination and enhanced carrier transport kinetics,the champion Mo/Sb_(2)Se_(3)/CdS(Al)/ITO/Ag photodetector exhibits self-powered and broadband characteristics,accompanied by simultaneously high responsivity of 0.9 A W^(-1)(at 11 nW cm^(-2)),linear dynamic range of 120 dB,impressive ON/OFF switching ratio over 10^(6)and signal-to-noise ratio of 10^(9),record total noise determined realistic detectivity of 4.78×10^(12)Jones,and ultra-fast response speed with rise/decay time of 24/75 ns,representing the top level for Sb_(2)Se_(3)-based photodetectors.This intriguing work opens up an avenue for its selfpowered broadband photodetector applications.展开更多
The CuZnSn(CZT) precursor thin films are grown by ion-beam sputtering Cu, Zn, Sn targets with different orders and then sputtering Se target to fabricate Cu_2ZnSnSe_4(CZTSe) absorber thin films on molybdenum substrate...The CuZnSn(CZT) precursor thin films are grown by ion-beam sputtering Cu, Zn, Sn targets with different orders and then sputtering Se target to fabricate Cu_2ZnSnSe_4(CZTSe) absorber thin films on molybdenum substrates. They are annealed in the same vacuum chamber at 400 ℃. The characterization methods of CZTSe thin films include X-ray diffraction(XRD), energy dispersive spectroscopy(EDS), scanning electron microscopy(SEM), and X-ray photoelectron spectra(XPS) in order to study the crystallographic properties, composition, surface morphology, electrical properties and so on. The results display that the CZTSe thin films got the strongest diffraction peak intensity and were with good crystalline quality and its morphology appeared smooth and compact with a sequence of Cu/Zn/Sn/Se, which reveals that the expected states for CZTSe are Cu^(1+), Zn^(2+), Sn^(4+), Se^(2).With the good crystalline quality and close to ideal stoichiometric ratio the resistivity of the CZTSe film with the sequence of Cu/Zn/Sn/Se is lower, whose optical band gap is about 1.50 eV.展开更多
Recently,the power conversion efficiency(PCE)of single-junction non-fullerene polymer solar cells(NF-PSCs)has surpassed 19%due to the fast development of novel donor polymers,NF-acceptors,device engineering,and interl...Recently,the power conversion efficiency(PCE)of single-junction non-fullerene polymer solar cells(NF-PSCs)has surpassed 19%due to the fast development of novel donor polymers,NF-acceptors,device engineering,and interlayer materials.The anode interlayer(AIL)plays a vital role in improving the efficiency and stability of PSCs.The challenges and opportunities in this research area encourage researchers to pursue great innovation in developing new materials and strategies for highly efficient NF-PSCs.This review summarizes the recent development of AIL materials and their modification strategies in single-junction NF-PSCs.Firstly,a brief introduction,key functions,basic requirements,and peculiar features of AILs when employed in NF-PSCs are discussed.Then,the impact of AIL materials(including organic,inorganic,and hybrid materials)on the PCE and the stability of NF-PSCs are described.Afterward,the fabrication of large-area devices and related issues are highlighted.The summary and the future challenges regarding efficient AIL are summarized in the last section of this review.展开更多
Antimony selenide(Sb_(2)Se_(3))has drawn tremendous research attentions in recent years as an environment-friendly and cost-efficient photovoltaic material.However,the intrinsic low carrier density and electrical cond...Antimony selenide(Sb_(2)Se_(3))has drawn tremendous research attentions in recent years as an environment-friendly and cost-efficient photovoltaic material.However,the intrinsic low carrier density and electrical conductivity limited its scope of applications.In this work,an effective ion doping strategy was implemented to improve the electrical and photoelectrical performances of Sb_(2)Se_(3) thin films.The Sn-doped and I-doped Sb_(2)Se_(3) thin films with controllable chemical composition can be prepared by magnetron sputtering combined with post-selenization treatment based on homemade plasma sintered targets.As a result,the Sn-doped Sb_(2)Se_(3) thin film exhibited a great increase in carrier density by several orders of magnitude,by contrast,a less increase with one order of magnitude was achieved for the Idoped Sb_(2)Se_(3) thin film.Additionally,such cation or anion doping could simultaneously modify the conduction type of Sb_(2)Se_(3),enabling the first fabrication of a substrate structured Sb_(2)Se_(3)-based quasihomojunction thin film solar cell with configuration of Mo/Sb_(2)Se_(3)-Sn/Sb_(2)Se_(3)-I/ITO/Ag.The obtained power conversion efficiency exceeding 2%undoubtedly demonstrated its attractive photovoltaic application potential and further investigation necessity.展开更多
Two-dimensional transition metal dichalcogenides are considered promising materials for next-generation photonics and nano-optical devices. Although many previous reports have shown saturable absorption of molybdenum ...Two-dimensional transition metal dichalcogenides are considered promising materials for next-generation photonics and nano-optical devices. Although many previous reports have shown saturable absorption of molybdenum diselenide(Mo Se2), these nonlinear optical(NLO) properties of Mo Se2 were measured in separate works and under different conditions with their hot-carrier relaxations. Here, we conducted a series of coherent studies on the NLO properties of few-layer Mo Se2 via open-aperture Z-scan and degenerate pump-probe techniques. These measurements were taken to test the materials' capabilities as a slow-saturable absorber. A slowabsorber model was employed to analyze the NLO measurements, and the results show that the NLO modulation depth was modeled to be 7.4% and 15.1% for the linear absorption coefficients of 5.22 cm-1 and 6.51 cm-1,respectively. The corresponding saturated intensities were modeled to be 39.37 MW∕cm2 and 234.75 MW∕cm2,respectively. The excitation carrier recovery time of few-layer Mo Se2 was measured by degenerate pump-probe techniques to be ～220 ps. These nonlinear optical performances make it a promising slow-saturable absorber for passive mode locking in femtosecond lasers.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62104156,62074102)the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2023A1515011256,2022A1515010979)China+1 种基金Science and Technology plan project of Shenzhen(Grant Nos.20220808165025003,20200812000347001)Chinasupported by the open foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Guangxi University(Grant No.2022GXYSOF13)。
文摘Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of flexible Sb_(2)Se_(3) photovoltaic devices is temporarily limited by the complicated intrinsic defects and the undesirable contact interfaces.Herein,a high-quality Sb_(2)Se_(3) absorber layer with large crystal grains and benign [hkl] growth orientation can be first prepared on a Mo foil substrate.Then NaF intermediate layer is introduced between Mo and Sb_(2)Se_(3),which can further optimize the growth of Sb_(2)Se_(3)thin film.Moreover,positive Na ion diffusion enables it to dramatically lower barrier height at the back contact interface and passivate harmful defects at both bulk and heterojunction.As a result,the champion substrate structured Mo-foil/Mo/NaF/Sb_(2)Se_(3)/CdS/ITO/Ag flexible thin-film solar cell delivers an obviously higher efficiency of 8.03% and a record open-circuit voltage(V_(OC)) of 0.492 V.This flexible Sb_(2)Se_(3) device also exhibits excellent stability and flexibility to stand large bending radius and multiple bending times,as well as superior weak light photo-response with derived efficiency of 12.60%.This work presents an effective strategy to enhance the flexible Sb_(2)Se_(3) device performance and expand its potential photovoltaic applications.
基金supported by the National Natural Science Foundation of China(62074102)the Guangdong Basic and Applied Basic Research Foundation(2022A1515010979)+1 种基金the Key Project of Department of Education of Guangdong Province(2018KZDXM059)the Science and Technology plan project of Shenzhen(20220808165025003)。
文摘Antimony selenide(Sb_(2)Se_(3))is a potential photovoltaic(PV)material for next-generation solar cells and has achieved great development in the last several years.The properties of Sb_(2)Se_(3)absorber and back contact influence the PV performances of Sb_(2)Se_(3)solar cells.Hence,optimization of back contact characteristics and absorber orientation are crucial steps in raising the power conversion efficiency(PCE)of Sb_(2)Se_(3)solar cells.In this work,MoO2was introduced as an intermediate layer(IL)in Sb_(2)Se_(3)solar cells,and comparative investigations were conducted.The growth of(211)-oriented Sb_(2)Se_(3)with large grains was facilitated by introducing the MoO2IL with suitable thickness.The MoO2IL substantially lowered the back contact barrier and prevented the formation of voids at the back contact,which reduced the thickness of the MoSe2interface layer,inhibited carrier recombination,and minimized bulk and interfacial defects in devices.Subsequently,significant optimization enhanced the open-circuit voltage(VOC)of solar cells from 0.481 V to 0.487 V,short-circuit current density(JSC)from 23.81 m A/cm^(2)to 29.29 m A/cm^(2),and fill factor from 50.28%to 57.10%,which boosted the PCE from 5.75%to 8.14%.
基金supported by the National Natural Science Foundation of China(No.62074102)Natural Science Foundation of Guangdong Province(2020A1515010805)China+1 种基金the Key Project of Department of Education of Guangdong Province(No.2018KZDXM059)Chinathe Science and Technology plan project of Shenzhen(20200812000347001,JCYJ20190808153409238)China。
文摘Photoelectrochemical(PEC) cells involved with semiconductor electrodes can simultaneously absorb solar energy and perform chemical reactions, which are considered as an attractive strategy to produce renewable and clean hydrogen energy. Sb_(2)Se_(3) has been widely investigated in constructing PEC photocathodes benefitting of its low toxicity, suitable band gap, superior optoelectronic properties, and outstanding photocorrosion stability. We first present a brief overview of basic concepts and principles of PEC water splitting as well as a comparison between Sb_(2)Se_(3) and other numerous candidates. Then the material characteristics and preparation methods of Sb_(2)Se_(3) are introduced. The development of Sb_(2)Se_(3)-based photocathodes in PEC water splitting with various architectures and engineering efforts(i.e., absorber engineering, interfaces engineering, co-catalyst engineering and tandem engineering) to improve solar-to-hydrogen(STH) efficiency are highlighted. Finally, we debate the possible future directions to further explore the researching fields of Sb_(2)Se_(3)-based photocathodes with a strongly positive outlook in PEC processed solar hydrogen production.
基金supported by the National Key R&D Program of China(No.2018YFE0203400)the Science and Technology plan project of Shenzhen(JCYJ20190808120001755)+1 种基金the National Natural Science Foundation of China(No.62074102)the Key Project of Department of Education of Guangdong Province(No.2018KZDXM059)China。
文摘In recent years,Cu_(2)ZnSnS_(4)(CZTS)semiconductor materials have received intensive attention in the field of thin-film solar cells owing to its non-toxic and low-cost elements.In this work,double-pressure sputtering technology is applied to obtain highly efficient and ultra-thin(-450 nm)pure Cu_(2)ZnSnS_(4)(CZTS)solar cell.Using mixed materials with sulfides and copper powder as a quaternary target via spark plasma sintering(SPS)method and adopting double-layer sputtering(high+low pressure),a highly adhesive and large-grained CZTS thin film is achieved.As a result,the damage to the surface of Mo contact is decreased so that the reflectivity of incident light can be improved.Moreover,the composition of CZTS film was more uniform and the secondary phase separation at the Mo interface was reduced.Therefore,the interface defect state and deep level defect density in corresponding device with double-pressure is reduced and the ratio of depletion thickness to absorption layer thickness can reached to 0.58,which promoted the collection of photogenerated carriers.Finally,an efficiency of 9.3%for ultra-thin(~450 nm)CZTS film solar cell is obtained.
基金supported by the National Key R&D Program of China(no.2018YFE0203400)the National Natural Science Foundation of China(no.62074102)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(no.2022A1515010979)the Science and Technology plan project of Shenzhen(nos.JCYJ20190808120001755 and 20220808165025003)。
文摘Kesterite Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)has attracted considerable attention as a non-toxic and earthabundant solar cell material.During selenization of CZTSSe film at high temperature,the reaction between CZTSSe and Mo is one of the main reasons that result in unfavorable absorber and interface quality,which leads to large open circuit voltage deficit(VOC-def)and low fill factor(FF).Herein,a WO_(3)intermediate layer introduced at the back interface can effectually inhibit the unfavorable interface reaction between absorber and back electrode in the preliminary selenization progress;thus high-quality crystals are obtained.Through this back interface engineering,the traditional problems of phase segregation,voids in the absorber and over thick Mo(S,Se)_(2)at the back interface can be well solved,which greatly lessens the recombination in the bulk and at the interface.The increased minority carrier diffusion length,decreased barrier height at back interface contact and reduced deep acceptor defects give rise to systematic improvement in VOCand FF,finally a 12.66%conversion efficiency for CZTSSe solar cell has been achieved.This work provides a simple way to fabricate highly efficient solar cells and promotes a deeper understanding of the function of intermediate layer at back interface in kesterite-based solar cells.
文摘Al2O3 films were prepared using electron beam evaporation at room temperature. The samples were irradiated with oxygen plasma under different energy. The variations in average surface defect density and root mean square (RMS) surface roughness were characterized using an optical microscope and an atomic force microscope. Surface average defect density increased after plasma treatment. The RMS surface roughness of the samples decreased from 1.92 nm to 1.26 nm because of surface atom restructuring after oxygen plasma conditioning. A 355 nm laser-induced damage experiment indicated that the as-grown sample with the lowest defect density exhibited a higher laser-induced damage threshold (1.12 J/cm2) than the other treated samples. Laser-induced damage images revealed that defect is one of the key factors that affect laser-induced damage on Al2O3 films.
基金supported by National Natural Science Foundation of China(No.62104156,62074102)Guangdong Basic and Applied Basic Research Foundation(2020A1515010805,2022A1515010979)China+1 种基金Science and Technology plan project of Shenzhen(20200812000347001,20220808165025003)Chinasupported by open foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,Guangxi University(Grant No.2022GXYSOF13)。
文摘Antimony selenide(Sb_(2)Se_(3))is a promising candidate for photodetector applications boasting unique material benefits and remarkable optoelectronic properties.Achieving high-performance self-powered Sb_(2)Se_(3)photodetector through a synergistic regulation of absorber layer and heterojunction interface demonstrates great potential and needs essential investigation.In this study,an effective two-step thermodynamic/kinetic deposition technique containing sputtered and selenized Sb precursor is implemented to induce self-assembled growth of Sb_(2)Se_(3)light absorbing thin film with large crystal grains and desirable[hk1]orientation,presenting considerable thin-film photodetector performance.Furthermore,aluminum(Al^(3+))cation dopant is introduced to modify the optoelectronic properties of CdS buffer layer,and further optimize the Sb_(2)Se_(3)/CdS(Al)heterojunction interface quality.Thanks to the suppressed carrier recombination and enhanced carrier transport kinetics,the champion Mo/Sb_(2)Se_(3)/CdS(Al)/ITO/Ag photodetector exhibits self-powered and broadband characteristics,accompanied by simultaneously high responsivity of 0.9 A W^(-1)(at 11 nW cm^(-2)),linear dynamic range of 120 dB,impressive ON/OFF switching ratio over 10^(6)and signal-to-noise ratio of 10^(9),record total noise determined realistic detectivity of 4.78×10^(12)Jones,and ultra-fast response speed with rise/decay time of 24/75 ns,representing the top level for Sb_(2)Se_(3)-based photodetectors.This intriguing work opens up an avenue for its selfpowered broadband photodetector applications.
基金Project supported by the National Natural Science Foundation of China(No.61404086)the Basical Research Program of Shenzhen(Nos.JCYJ20150324140036866,JCYJ20150324141711581)the Natural Science Foundation of SZU(No.2014017)
文摘The CuZnSn(CZT) precursor thin films are grown by ion-beam sputtering Cu, Zn, Sn targets with different orders and then sputtering Se target to fabricate Cu_2ZnSnSe_4(CZTSe) absorber thin films on molybdenum substrates. They are annealed in the same vacuum chamber at 400 ℃. The characterization methods of CZTSe thin films include X-ray diffraction(XRD), energy dispersive spectroscopy(EDS), scanning electron microscopy(SEM), and X-ray photoelectron spectra(XPS) in order to study the crystallographic properties, composition, surface morphology, electrical properties and so on. The results display that the CZTSe thin films got the strongest diffraction peak intensity and were with good crystalline quality and its morphology appeared smooth and compact with a sequence of Cu/Zn/Sn/Se, which reveals that the expected states for CZTSe are Cu^(1+), Zn^(2+), Sn^(4+), Se^(2).With the good crystalline quality and close to ideal stoichiometric ratio the resistivity of the CZTSe film with the sequence of Cu/Zn/Sn/Se is lower, whose optical band gap is about 1.50 eV.
基金Key Project of Department of Education of Guangdong Province,Grant/Award Number:2018KZDXM059National Key Research and Development Program of China,Grant/Award Number:2017YFA0206600+2 种基金National Natural Science Foundation of China,Grant/Award Numbers:21922505,62074102Science and Technology Plan Project of Shenzhen,Grant/Award Number:JCYJ20190808153409238Strategic Priority Research Program of Chinese Academy of Sciences,Grant/Award Number:XDB36000000。
文摘Recently,the power conversion efficiency(PCE)of single-junction non-fullerene polymer solar cells(NF-PSCs)has surpassed 19%due to the fast development of novel donor polymers,NF-acceptors,device engineering,and interlayer materials.The anode interlayer(AIL)plays a vital role in improving the efficiency and stability of PSCs.The challenges and opportunities in this research area encourage researchers to pursue great innovation in developing new materials and strategies for highly efficient NF-PSCs.This review summarizes the recent development of AIL materials and their modification strategies in single-junction NF-PSCs.Firstly,a brief introduction,key functions,basic requirements,and peculiar features of AILs when employed in NF-PSCs are discussed.Then,the impact of AIL materials(including organic,inorganic,and hybrid materials)on the PCE and the stability of NF-PSCs are described.Afterward,the fabrication of large-area devices and related issues are highlighted.The summary and the future challenges regarding efficient AIL are summarized in the last section of this review.
基金supported by Natural Science Foundation of Guangdong Province(2020A1515010805)ChinaNational Natural Science Foundation of China(No.62074102)+1 种基金Key Project of Department of Education of Guangdong Province(No.2018KZDXM059)ChinaScience and Technology plan project of Shenzhen(JCYJ20190808153409238)China.
文摘Antimony selenide(Sb_(2)Se_(3))has drawn tremendous research attentions in recent years as an environment-friendly and cost-efficient photovoltaic material.However,the intrinsic low carrier density and electrical conductivity limited its scope of applications.In this work,an effective ion doping strategy was implemented to improve the electrical and photoelectrical performances of Sb_(2)Se_(3) thin films.The Sn-doped and I-doped Sb_(2)Se_(3) thin films with controllable chemical composition can be prepared by magnetron sputtering combined with post-selenization treatment based on homemade plasma sintered targets.As a result,the Sn-doped Sb_(2)Se_(3) thin film exhibited a great increase in carrier density by several orders of magnitude,by contrast,a less increase with one order of magnitude was achieved for the Idoped Sb_(2)Se_(3) thin film.Additionally,such cation or anion doping could simultaneously modify the conduction type of Sb_(2)Se_(3),enabling the first fabrication of a substrate structured Sb_(2)Se_(3)-based quasihomojunction thin film solar cell with configuration of Mo/Sb_(2)Se_(3)-Sn/Sb_(2)Se_(3)-I/ITO/Ag.The obtained power conversion efficiency exceeding 2%undoubtedly demonstrated its attractive photovoltaic application potential and further investigation necessity.
基金Science Foundation Ireland(SFI)(12/IA/1306)Seventh Framework Programme(FP7)(ISLA project no.287732)+4 种基金National Natural Science Foundation of China(NSFC)(61522510,61675217,11704261,11575118)Strategic Priority Research Program of Chinese Academy of Sciences(CAS)(XDB16030700)Key Research Program of Frontier Science of Chinese Academy of Sciences(QYZDBSSW-JSC041)the Program of Shanghai Academic Research Leader(17XD1403900)Shenzhen Key Lab Fund(ZDSYS20170228105421966)
文摘Two-dimensional transition metal dichalcogenides are considered promising materials for next-generation photonics and nano-optical devices. Although many previous reports have shown saturable absorption of molybdenum diselenide(Mo Se2), these nonlinear optical(NLO) properties of Mo Se2 were measured in separate works and under different conditions with their hot-carrier relaxations. Here, we conducted a series of coherent studies on the NLO properties of few-layer Mo Se2 via open-aperture Z-scan and degenerate pump-probe techniques. These measurements were taken to test the materials' capabilities as a slow-saturable absorber. A slowabsorber model was employed to analyze the NLO measurements, and the results show that the NLO modulation depth was modeled to be 7.4% and 15.1% for the linear absorption coefficients of 5.22 cm-1 and 6.51 cm-1,respectively. The corresponding saturated intensities were modeled to be 39.37 MW∕cm2 and 234.75 MW∕cm2,respectively. The excitation carrier recovery time of few-layer Mo Se2 was measured by degenerate pump-probe techniques to be ～220 ps. These nonlinear optical performances make it a promising slow-saturable absorber for passive mode locking in femtosecond lasers.
