Color tunable quantum dots（QDs） based on the Cu, Mn, Ag co-doped Zn In S core and Zn S outer-shell were synthesized by using an eco-friendly method. Core-shell doped QDs with the average size of 3.85 nm were obtaine...Color tunable quantum dots（QDs） based on the Cu, Mn, Ag co-doped Zn In S core and Zn S outer-shell were synthesized by using an eco-friendly method. Core-shell doped QDs with the average size of 3.85 nm were obtained by using a one-pot synthesis followed by a hot injection with n-dodecanethiol（DDT） and oleylamine（OLA） as stabilizers in oil phase. Cu, Mn and Ag ions were introduced as single-dopant or co-dopants during the synthesis, providing an effective means to control the emission color of the QDs. The as-synthesized QDs showed photoluminescence emission ranging from green（530 nm） to near-red（613 nm）, adjusted by doping components, dopant concentration, and Zn/In ratio. Importantly, quasi-white emission has been achieved by controlling the concentration of co-doped metal ions（Mn, Cu and Ag）. The primary results demonstrated the promising potential of co-doped QDs as alternative materials for future high quality white LED applications.展开更多
The stabilization of the formamidinium lead iodide(FAPbI_(3))structure is pivotal for the development of efficient photovoltaic devices.Employing two-dimensional(2D)layers to passivate the threedimensional(3D)perovski...The stabilization of the formamidinium lead iodide(FAPbI_(3))structure is pivotal for the development of efficient photovoltaic devices.Employing two-dimensional(2D)layers to passivate the threedimensional(3D)perovskite is essential for maintaining the a-phase of FAPbI_(3) and enhancing the power conversion efficiency(PCE)of perovskite solar cells(PSCs).However,the role of bulky ligands in the phase management of 2D perovskites,crucial for the stabilization of FAPbI_(3),has not yet been elucidated.In this study,we synthesized nanoscale 2D perovskite capping crusts with<n>=1 and 2 Ruddlesden-Popper(RP)perovskite layers,respectively,which form a type-Ⅱ 2D/3D heterostructure.This heterostructure stabilizes the a-phase of FAPbI_(3),and facilitates ultrafast carrier extraction from the 3D perovskite network to transport contact layer.We introduced tri-fluorinated ligands to mitigate defects caused by the halide vacancies and uncoordinated Pb^(2+)ions,thereby reducing nonradiative carrier recombination and extending carrier lifetime.The films produced were incorporated into PSCs that not only achieved a PCE of 25.39%but also maintained 95%of their initial efficiency after 2000 h of continuous light exposure without encapsulation.These findings underscore the effectiveness of a phase-pure 2D/3D heterostructure-terminated film in inhibiting phase transitions passivating the iodide anion vacancy defects,facilitating the charge carrier extraction,and boosting the performance of optoelectronic devices.展开更多
Organic-inorganic hybrid two-dimensional(2D)ruddlesden-popper(RP)perovskites with fantastic optoelectronic properties and good stability have attracted tremendous attention for the potential applications in photovolta...Organic-inorganic hybrid two-dimensional(2D)ruddlesden-popper(RP)perovskites with fantastic optoelectronic properties and good stability have attracted tremendous attention for the potential applications in photovoltaics and electroluminescence.Recently,a new allinorganic Cs2PbI2Cl22D perovskite has been proposed with excellent excitonic absorption and improved ambient and thermal stability.Herein,an interesting light-induced phase transition and photochromism in the Cs2PbI2Cl2were reported.Under low fluence light pumping,the room temperature photoluminescence(PL)of Cs2PbI2Cl2is dominated by a weak violet excitonic emission peaked at 412 nm.Surprisingly,the emission color gradually changes from violet to bright red while increasing the laser pumping fluence.This photochromic effect is determined to be caused by forming CsPbI3phase within the Cs2PbI2Cl2crystals,which is efficiently driven by thermal energy.Due to protection by the Cs2PbI2Cl2matrix,the embedded CsPbI3nanocrystals show improved stability than standard pure CsPbI3.Therefore,the Cs2PbI2Cl2perovskite with photochromic feature may find applications in optical encryption,as preliminarily shown in this work.展开更多
基金Projects(61675049,61377046,61144010,61177021) supported by the National Natural Science Foundation of China
文摘Color tunable quantum dots（QDs） based on the Cu, Mn, Ag co-doped Zn In S core and Zn S outer-shell were synthesized by using an eco-friendly method. Core-shell doped QDs with the average size of 3.85 nm were obtained by using a one-pot synthesis followed by a hot injection with n-dodecanethiol（DDT） and oleylamine（OLA） as stabilizers in oil phase. Cu, Mn and Ag ions were introduced as single-dopant or co-dopants during the synthesis, providing an effective means to control the emission color of the QDs. The as-synthesized QDs showed photoluminescence emission ranging from green（530 nm） to near-red（613 nm）, adjusted by doping components, dopant concentration, and Zn/In ratio. Importantly, quasi-white emission has been achieved by controlling the concentration of co-doped metal ions（Mn, Cu and Ag）. The primary results demonstrated the promising potential of co-doped QDs as alternative materials for future high quality white LED applications.
基金the Science and Technology Development Fund,Macao SAR(FDCT-0082/2021/A2,0010/2022/AMJ,0060/2023/RIA1,0136/2022/A3,006/2022/ALC,and EF044/IAPME-HG/2022/MUST)UM’s research fund(MYRG2022-00241IAPME,MYRG-GRG2023-00065-IAPME-UMDF,and MYRGCRG2022-00009-FHS)+8 种基金the research fund from Wuyi University(EF38/IAPME-XGC/2022/WYU)Shaanxi Fundamental Science Research Project for Mathematics and Physics(22JSY015 and 23JSY005)Shaanxi Province science and technology activities for overseas students selected funding project(2023015)the State Key Laboratory for Strength and Vibration of Mechanical Structures(SV2023-KF-18)Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic Systems(2023B1212010003)the China Fundamental Research Funds for the Central Universities,Young Talent Fund of Xi’an Association for Science and Technology(959202313020)the project of Innovative Team of Shaanxi Province(2020TD-001)the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(NY223053)the National Natural Science Foundation of China(61935017,62105292,62175268,62288102 and 62304111)。
文摘The stabilization of the formamidinium lead iodide(FAPbI_(3))structure is pivotal for the development of efficient photovoltaic devices.Employing two-dimensional(2D)layers to passivate the threedimensional(3D)perovskite is essential for maintaining the a-phase of FAPbI_(3) and enhancing the power conversion efficiency(PCE)of perovskite solar cells(PSCs).However,the role of bulky ligands in the phase management of 2D perovskites,crucial for the stabilization of FAPbI_(3),has not yet been elucidated.In this study,we synthesized nanoscale 2D perovskite capping crusts with<n>=1 and 2 Ruddlesden-Popper(RP)perovskite layers,respectively,which form a type-Ⅱ 2D/3D heterostructure.This heterostructure stabilizes the a-phase of FAPbI_(3),and facilitates ultrafast carrier extraction from the 3D perovskite network to transport contact layer.We introduced tri-fluorinated ligands to mitigate defects caused by the halide vacancies and uncoordinated Pb^(2+)ions,thereby reducing nonradiative carrier recombination and extending carrier lifetime.The films produced were incorporated into PSCs that not only achieved a PCE of 25.39%but also maintained 95%of their initial efficiency after 2000 h of continuous light exposure without encapsulation.These findings underscore the effectiveness of a phase-pure 2D/3D heterostructure-terminated film in inhibiting phase transitions passivating the iodide anion vacancy defects,facilitating the charge carrier extraction,and boosting the performance of optoelectronic devices.
基金supported by the Macao Science and Technology Development Fund(FDCT-116/2016/A3,FDCT-091/2017/A2,FDCT-014/2017/AMJ and FDCT-199/2017/A3)Start-up Research Grant Fund from University of Macao(SRG2016-00002-FST)+3 种基金Research and Development Grant for Chair Professor Fund from University of Macao(CPG2018-00026-FST)Research Grant(SRG201600087-FST,MYRG2018-00148-IAPME and MYRG2018-00142-IAPME)from University of Macaothe National Natural Science Foundation of China(91733302,61935017 and 61605073)the Natural Science Foundation of Guangdong Province of China(2019A1515012186)。
文摘Organic-inorganic hybrid two-dimensional(2D)ruddlesden-popper(RP)perovskites with fantastic optoelectronic properties and good stability have attracted tremendous attention for the potential applications in photovoltaics and electroluminescence.Recently,a new allinorganic Cs2PbI2Cl22D perovskite has been proposed with excellent excitonic absorption and improved ambient and thermal stability.Herein,an interesting light-induced phase transition and photochromism in the Cs2PbI2Cl2were reported.Under low fluence light pumping,the room temperature photoluminescence(PL)of Cs2PbI2Cl2is dominated by a weak violet excitonic emission peaked at 412 nm.Surprisingly,the emission color gradually changes from violet to bright red while increasing the laser pumping fluence.This photochromic effect is determined to be caused by forming CsPbI3phase within the Cs2PbI2Cl2crystals,which is efficiently driven by thermal energy.Due to protection by the Cs2PbI2Cl2matrix,the embedded CsPbI3nanocrystals show improved stability than standard pure CsPbI3.Therefore,the Cs2PbI2Cl2perovskite with photochromic feature may find applications in optical encryption,as preliminarily shown in this work.
