Organic-inorganic halide perovskites(OHPs)have been intensively studied for application in solar cells with high conversion efficiency exceeding 22%.The unique electrical and optical properties of OHPs have led to the...Organic-inorganic halide perovskites(OHPs)have been intensively studied for application in solar cells with high conversion efficiency exceeding 22%.The unique electrical and optical properties of OHPs have led to their use in optoelectronic device applications beyond photovoltaics,such as light-emitting diodes,photodetectors,transistors.New information storage technologies and computing architectures are being researched extensively with the aim of addressing the growing challenge of approaching end of Moore's law and von Neumann bottleneck.As the fourth basic circuit element,memristor is a leading candidate with powerful capabilities in information storage and neuromorphic computing applications.Recently,OHPs have received growing attention as promising materials for memristors.In particular,their mixed ionic-electronic conduction ability paired with light sensitivity provide OHPs with the opportunity to display novel functions such as optical-erase memory,optogenetics-inspired synaptic functions,and lightaccelerated learning capability.This review covers recent advances in OHP-based memristors development including memristive mechanism and analytical models,universal memristive characteristics for memory and neuromorphic computing applications,and novel multi-functionalization.Challenges and future prospects of OHP-based memristors are also discussed.展开更多
Metal halide perovskites are crystalline materials originally developed out of scientific curiosity. They have shown great potential as active materials in optoelectronic applications. In the last 6 years, their certi...Metal halide perovskites are crystalline materials originally developed out of scientific curiosity. They have shown great potential as active materials in optoelectronic applications. In the last 6 years, their certified photovoltaic efficiencies have reached 22.1%. Compared to bulk halide perovskites, low-dimensional ones exhibited novel physical properties. The photoluminescence quantum yields of perovskite quantum dots are close to 100%. The external quantum efficiencies and current efficiencies of perovskite quantum dot light-emitting diodes have reached 8% and 43 cd A^(-1),respectively, and their nanowire lasers show ultralow-threshold room-temperature lasing with emission tunability and ease of synthesis. Perovskite nanowire photodetectors reached a responsivity of 10 A W^(-1)and a specific normalized detectivity of the order of 10^(12 )Jones. Different from most reported reviews focusing on photovoltaic applications, we summarize the rapid progress in the study of low-dimensional perovskite materials, as well as their promising applications in optoelectronic devices. In particular, we review the wide tunability of fabrication methods and the state-of-the-art research outputs of low-dimensional perovskite optoelectronic devices. Finally, the anticipated challenges and potential for this exciting research are proposed.展开更多
Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conv...Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conversion efficiency(PCE) has boosted from 3.8% to 25.2% over the past ten years. Despite the rapid progress in PCE, the device stability is a key issue that impedes the commercialization of PSCs. Recently, all-inorganic cesium lead halide perovskites have attracted much attention due to their better stability compared with their organic-inorganic counterpart. In this progress report, we summarize the properties of CsPb(IxBr1-x)3 and their applications in solar cells. The current challenges and corresponding solutions are discussed. Finally, we share our perspectives on CsPb(IxBr1-x)3 solar cells and outline possible directions to further improve the device performance.展开更多
High-performance multiphoton-pumped lasers based on cesium lead halide perovskite nanostructures are promising for nonlinear optics and practical frequency upconversion devices in integrated photonics. However, the pe...High-performance multiphoton-pumped lasers based on cesium lead halide perovskite nanostructures are promising for nonlinear optics and practical frequency upconversion devices in integrated photonics. However, the performance of such lasers is highly dependent on the quality of the material and cavity, which makes their fabrication challenging. Herein, we demonstrate that cesium lead halide perovskite triangular nanorods fabricated via vapor methods can serve as gain media and effective cavities for multiphoton-pumped lasers. We observed blue-shifts of the lasing modes in the excitation fluence-dependent lasing spectra at increased excitation powers, which fits well with the dynamics of Burstein-Moss shifts caused by the band filling effect. Moreover, efficient multiphoton lasing in CsPbBr3 nanorods can be realized in a wide excitation wavelength range （700-1,400 nm）. The dynamics of multiphoton lasing were investigated by time-resolved photoluminescence spectroscopy, which indicated that an electron-hole plasma is responsible for the multiphoton-pumped lasing. This work could lead to new opportunities and applications for cesium lead halide perovskite nanostructures in frequency upconversion lasing devices and optical interconnect systems.展开更多
Lead-based halide perovskites have emerged as excellent semiconductors for a broad range of optoelectronic applications, such as photovoltaics, lighting, lasing and photon detection. However, toxicity of lead and poor...Lead-based halide perovskites have emerged as excellent semiconductors for a broad range of optoelectronic applications, such as photovoltaics, lighting, lasing and photon detection. However, toxicity of lead and poor stability still represent significant challenges. Fortunately, halide double perovskite materials with formula of A_2M(I)M(III)X_6 or A_2M(IV)X_6 could be potentially regarded as stable and green alternatives for optoelectronic applications, where two divalent lead ions are substituted by combining one monovalent and one trivalent ions, or one tetravalent ion. Here, the article provides an up-to-date review on the developments of halide double perovskite materials and their related optoelectronic applications including photodetectors, X-ray detectors, photocatalyst, light-emitting diodes and solar cells. The synthesized halide double perovskite materials exhibit exceptional stability, and a few possess superior optoelectronic properties. However, the number of synthesized halide double perovskites is limited, and more limited materials have been developed for optoelectronic applications to date. In addition, the band structures and carrier transport properties of the materials are still not desired, and the films still manifest low quality for photovoltaic applications. Therefore, we propose that continuing e orts are needed to develop more halide double perovskites, modulate the properties and grow high-quality films, with the aim of opening the wild practical applications.展开更多
Cesium lead iodide （CsPbIa）, in its black perovskite phase, has a suitable bandgap and high quantum efficiency for photovoltaic applications. However, CsPbI3 tends to crystalize into a yellow non-perovskite phase, w...Cesium lead iodide （CsPbIa）, in its black perovskite phase, has a suitable bandgap and high quantum efficiency for photovoltaic applications. However, CsPbI3 tends to crystalize into a yellow non-perovskite phase, which has poor optoelectronic properties, at room temperature. Therefore, controlling the phase transition in CsPbI3 is critical for practical application of this material. Here we report a systematic study of the phase transition of one-dimensional CsPbI3 nanowires and their corresponding structural, optical, and electrical properties. We show the formation of perovskite black phase CsPbIa nanowires from the non-perovskite yellow phase through rapid thermal quenching. Post-transformed black phase CsPbI3 nanowires exhibit increased photoluminescence emission intensity with a shrinking of the bandgap from 2.78 to 1.76 eV. The perovskite nanowires were photoconductive and showed a fast photoresponse and excellent stability at room temperature. These promising optical and electrical properties make the perovskite CsPbI3 nanowires attractive for a variety of nanoscale optoelectronic devices.展开更多
Halide perovskites have emerged as superstar materials for optoelectronic devices. Besides the fever of research in solar cells, these materials show great promise on light emitting diodes(LEDs), photodetectors and la...Halide perovskites have emerged as superstar materials for optoelectronic devices. Besides the fever of research in solar cells, these materials show great promise on light emitting diodes(LEDs), photodetectors and lasers as well. Rapid advances in bulk perovskite materials aroused universal interest for the development of perovskite nanocrystals, inspired by the great progress of classic colloidal semiconductor quantum dots. Perovskite nanocrystals have been synthesized based on solution process and exhibited high luminescence quantum yield, sharp emission peak, and emission color tunability. Significant progresses have been made about the application of perovskite nanocrystals for LED and lasers in recent years. In this paper, we will comprehensively introduce the synthesis strategies, physical and chemical characteristics, as well as their applications in optoelectronic devices.展开更多
The synthesis of high quality all-inorganic perovskite nanowires needs the harsh conditions,complex process and precision instruments,which are not beneficial to their extensive application.Here,all-inorganic perovski...The synthesis of high quality all-inorganic perovskite nanowires needs the harsh conditions,complex process and precision instruments,which are not beneficial to their extensive application.Here,all-inorganic perovskite ce- sium lead bromine (CsPbBr3)nanowires (NWs)are demonstrated with the combination of solution-phase process and halide exchange technology.A metal-semiconductor-metal structure CsPbBr3 nanowire photodetector was prepared, which showed a detectivity as high as 1.7×10^11 cm Hz^1/2W^-1 (Jones)with rapid response time (The rise and decay time are 10ms and 22 ms,respectively).Moreover,our photodetectors have high stability under ultraviolet (UV)light,high temperature and humidity.展开更多
Halide perovskites have emerged as the next generation of optoelectronic materials and their remarkable performances have been attractive in the fields of solar cells,light-emitting diodes,photodetectors,etc.In additi...Halide perovskites have emerged as the next generation of optoelectronic materials and their remarkable performances have been attractive in the fields of solar cells,light-emitting diodes,photodetectors,etc.In addition,halide perovskites have been reported as an attractive new class of X-ray direct detecting materials recently,owning to the strong X-ray stopping capacity,excellent carrier transport,high sensitivity,and cost-effective manufacturing.Meanwhile,perovskite based direct Xray imagers have been successfully demonstrated as well.In this review article,we firstly introduced some fundamental principles of direct X-ray detection and imaging,and summarized the advances of perovskite materials for these purposes and finally put forward some needful and feasible directions.展开更多
Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,m...Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,modulation,to transmission)for next-generation optoelectronic technology.Notably,the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade,while in the next decade,it will be primarily critical to promote their implantation in the next-generation optoelectronics.In this review,we first retrospect the historical research milestones of MHPs and their optoelectronic devices.Thereafter,we introduce the origin of the unique optoelectronic features of MHPs,based on which we highlight the tunability of these features via regulating the phase,dimensionality,composition,and geometry of MHPs.Then,we show that owing to the convenient property control of MHPs,various optoelectronic devices with target performance can be designed.At last,we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems.This review demonstrates the key role of MHPs played in the development of modern optoelectronics,which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.展开更多
A simple Cu（OAc）2 catalyzed Sonogashira coupling protocol is presented. It was found that the couplings of a variety of aryl halides with terminal alkynes were conducted smoothly to afford the corresponding desired ...A simple Cu（OAc）2 catalyzed Sonogashira coupling protocol is presented. It was found that the couplings of a variety of aryl halides with terminal alkynes were conducted smoothly to afford the corresponding desired products in moderate to excellent yields, using Cu（OAc）2 as the catalyst and Et3N as the solvent.展开更多
We report an in-situ fabrication of halide perovskite (CH3NH3PbX3,CH3NH3 =methylammonium,MA,X =Cl,Br,I) nanocrystals in polyvinylalcohol (PVA) nanofibers (MAPbX3@PVA nanofibers) through electrospinning a perovskite pr...We report an in-situ fabrication of halide perovskite (CH3NH3PbX3,CH3NH3 =methylammonium,MA,X =Cl,Br,I) nanocrystals in polyvinylalcohol (PVA) nanofibers (MAPbX3@PVA nanofibers) through electrospinning a perovskite precursor solution.With the content of the precursors increased,the resulting MAPbBr3 nanocrystals in PVA matrix changed the shape from ellipsoidal to pearl-like,and finely into rods-like.Optimized MAPbBr3@PVA nanofibers show strong polarized emission with the photoluminescence quantum yield of up to 72%.We reveal correlations between the shape of in-situ fabricated perovskite nanocrystals and the polarization degree of their emission by comparing experimental data from the single nanofiber measurements with theoretical calculations.Polarized emission of MAPbBr3@PVA nanofibers can be attributed to the dielectric confinement and quantum confinement effects.Moreover,nanofibers can be efficiently aligned by using parallel positioned conductor strips with an air gap as collector.A polarization ratio of 0.42 was achieved for the films of well-aligned MAPbBr3@PVA nanofibers with a macroscale size of 0.5 cm × 2 cm,which allows potential applications in displays,lasers,waveguides,etc.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)for Excellent Young Scholars(No.51422201)the NSFC Program(Nos.51701037,51732003,61774031,51872043,and 61574031)+3 种基金the“111”Project(No.B13013)the Fund from People's Government of Jilin Province(Nos.20180520186JH,and JJKH20190275KJ)the Project Funded by China Postdoctoral Science Foundation(No.2017M621189)Fundamental Research Funds for the Central Universities(No.JGPY201909).
文摘Organic-inorganic halide perovskites(OHPs)have been intensively studied for application in solar cells with high conversion efficiency exceeding 22%.The unique electrical and optical properties of OHPs have led to their use in optoelectronic device applications beyond photovoltaics,such as light-emitting diodes,photodetectors,transistors.New information storage technologies and computing architectures are being researched extensively with the aim of addressing the growing challenge of approaching end of Moore's law and von Neumann bottleneck.As the fourth basic circuit element,memristor is a leading candidate with powerful capabilities in information storage and neuromorphic computing applications.Recently,OHPs have received growing attention as promising materials for memristors.In particular,their mixed ionic-electronic conduction ability paired with light sensitivity provide OHPs with the opportunity to display novel functions such as optical-erase memory,optogenetics-inspired synaptic functions,and lightaccelerated learning capability.This review covers recent advances in OHP-based memristors development including memristive mechanism and analytical models,universal memristive characteristics for memory and neuromorphic computing applications,and novel multi-functionalization.Challenges and future prospects of OHP-based memristors are also discussed.
基金supported by the Doctoral Program of Higher Education(20130142120075)the Fundamental Research Funds for the Central Universities(HUST:2016YXMS032)National Key Research and Development Program of China(Grant No.2016YFB0700702)
文摘Metal halide perovskites are crystalline materials originally developed out of scientific curiosity. They have shown great potential as active materials in optoelectronic applications. In the last 6 years, their certified photovoltaic efficiencies have reached 22.1%. Compared to bulk halide perovskites, low-dimensional ones exhibited novel physical properties. The photoluminescence quantum yields of perovskite quantum dots are close to 100%. The external quantum efficiencies and current efficiencies of perovskite quantum dot light-emitting diodes have reached 8% and 43 cd A^(-1),respectively, and their nanowire lasers show ultralow-threshold room-temperature lasing with emission tunability and ease of synthesis. Perovskite nanowire photodetectors reached a responsivity of 10 A W^(-1)and a specific normalized detectivity of the order of 10^(12 )Jones. Different from most reported reviews focusing on photovoltaic applications, we summarize the rapid progress in the study of low-dimensional perovskite materials, as well as their promising applications in optoelectronic devices. In particular, we review the wide tunability of fabrication methods and the state-of-the-art research outputs of low-dimensional perovskite optoelectronic devices. Finally, the anticipated challenges and potential for this exciting research are proposed.
基金the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21572041 and 21772030)for the financial support
文摘Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conversion efficiency(PCE) has boosted from 3.8% to 25.2% over the past ten years. Despite the rapid progress in PCE, the device stability is a key issue that impedes the commercialization of PSCs. Recently, all-inorganic cesium lead halide perovskites have attracted much attention due to their better stability compared with their organic-inorganic counterpart. In this progress report, we summarize the properties of CsPb(IxBr1-x)3 and their applications in solar cells. The current challenges and corresponding solutions are discussed. Finally, we share our perspectives on CsPb(IxBr1-x)3 solar cells and outline possible directions to further improve the device performance.
基金Acknowledgements All authors are grateful to the National Natural Science Foundation of China （Nos. 51525202, 61574054, 61505051 and 61474040）, the Hunan province science and technology plan （Nos. 2014FJ2001 and 2014TT1004）, the Aid program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province, and the Fundamental Research Funds for the Central Universities.
文摘High-performance multiphoton-pumped lasers based on cesium lead halide perovskite nanostructures are promising for nonlinear optics and practical frequency upconversion devices in integrated photonics. However, the performance of such lasers is highly dependent on the quality of the material and cavity, which makes their fabrication challenging. Herein, we demonstrate that cesium lead halide perovskite triangular nanorods fabricated via vapor methods can serve as gain media and effective cavities for multiphoton-pumped lasers. We observed blue-shifts of the lasing modes in the excitation fluence-dependent lasing spectra at increased excitation powers, which fits well with the dynamics of Burstein-Moss shifts caused by the band filling effect. Moreover, efficient multiphoton lasing in CsPbBr3 nanorods can be realized in a wide excitation wavelength range （700-1,400 nm）. The dynamics of multiphoton lasing were investigated by time-resolved photoluminescence spectroscopy, which indicated that an electron-hole plasma is responsible for the multiphoton-pumped lasing. This work could lead to new opportunities and applications for cesium lead halide perovskite nanostructures in frequency upconversion lasing devices and optical interconnect systems.
基金supported by the Ministry of Education of China (IRT1148)the National Natural Science Foundation of China (U1732126, 11804166, 51602161, 51372119)+3 种基金the National Synergetic Innovation Center for Advanced Materials (SICAM)the China Postdoctoral Science Foundation (2018M630587)the Priority Academic Program Development of Jiangsu Higher Education Institutions (YX03001)the Natural Science Foundation of NJUPT (NY217091)
文摘Lead-based halide perovskites have emerged as excellent semiconductors for a broad range of optoelectronic applications, such as photovoltaics, lighting, lasing and photon detection. However, toxicity of lead and poor stability still represent significant challenges. Fortunately, halide double perovskite materials with formula of A_2M(I)M(III)X_6 or A_2M(IV)X_6 could be potentially regarded as stable and green alternatives for optoelectronic applications, where two divalent lead ions are substituted by combining one monovalent and one trivalent ions, or one tetravalent ion. Here, the article provides an up-to-date review on the developments of halide double perovskite materials and their related optoelectronic applications including photodetectors, X-ray detectors, photocatalyst, light-emitting diodes and solar cells. The synthesized halide double perovskite materials exhibit exceptional stability, and a few possess superior optoelectronic properties. However, the number of synthesized halide double perovskites is limited, and more limited materials have been developed for optoelectronic applications to date. In addition, the band structures and carrier transport properties of the materials are still not desired, and the films still manifest low quality for photovoltaic applications. Therefore, we propose that continuing e orts are needed to develop more halide double perovskites, modulate the properties and grow high-quality films, with the aim of opening the wild practical applications.
文摘Cesium lead iodide （CsPbIa）, in its black perovskite phase, has a suitable bandgap and high quantum efficiency for photovoltaic applications. However, CsPbI3 tends to crystalize into a yellow non-perovskite phase, which has poor optoelectronic properties, at room temperature. Therefore, controlling the phase transition in CsPbI3 is critical for practical application of this material. Here we report a systematic study of the phase transition of one-dimensional CsPbI3 nanowires and their corresponding structural, optical, and electrical properties. We show the formation of perovskite black phase CsPbIa nanowires from the non-perovskite yellow phase through rapid thermal quenching. Post-transformed black phase CsPbI3 nanowires exhibit increased photoluminescence emission intensity with a shrinking of the bandgap from 2.78 to 1.76 eV. The perovskite nanowires were photoconductive and showed a fast photoresponse and excellent stability at room temperature. These promising optical and electrical properties make the perovskite CsPbI3 nanowires attractive for a variety of nanoscale optoelectronic devices.
基金supported by the Start-up Funding from Shanghai Tech University,the Thousand Youth Talents Plan(21571129)Shanghai Key Research Program(16JC1402100)+5 种基金the National Natural Science Foundation of China(21571129,51572128,U1632118)the National Key Research Program(2016YFA0204000)Shanghai International Cooperation Project(16520720700)the National Natural Science Foundation of China-the Research Grants Council(NSFC-RGC)(5151101197)the National Key Basic Research Program of China(2014CB931702)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Halide perovskites have emerged as superstar materials for optoelectronic devices. Besides the fever of research in solar cells, these materials show great promise on light emitting diodes(LEDs), photodetectors and lasers as well. Rapid advances in bulk perovskite materials aroused universal interest for the development of perovskite nanocrystals, inspired by the great progress of classic colloidal semiconductor quantum dots. Perovskite nanocrystals have been synthesized based on solution process and exhibited high luminescence quantum yield, sharp emission peak, and emission color tunability. Significant progresses have been made about the application of perovskite nanocrystals for LED and lasers in recent years. In this paper, we will comprehensively introduce the synthesis strategies, physical and chemical characteristics, as well as their applications in optoelectronic devices.
基金supported by the National Natural Science Foundation of China (51372075)
文摘The synthesis of high quality all-inorganic perovskite nanowires needs the harsh conditions,complex process and precision instruments,which are not beneficial to their extensive application.Here,all-inorganic perovskite ce- sium lead bromine (CsPbBr3)nanowires (NWs)are demonstrated with the combination of solution-phase process and halide exchange technology.A metal-semiconductor-metal structure CsPbBr3 nanowire photodetector was prepared, which showed a detectivity as high as 1.7×10^11 cm Hz^1/2W^-1 (Jones)with rapid response time (The rise and decay time are 10ms and 22 ms,respectively).Moreover,our photodetectors have high stability under ultraviolet (UV)light,high temperature and humidity.
文摘Halide perovskites have emerged as the next generation of optoelectronic materials and their remarkable performances have been attractive in the fields of solar cells,light-emitting diodes,photodetectors,etc.In addition,halide perovskites have been reported as an attractive new class of X-ray direct detecting materials recently,owning to the strong X-ray stopping capacity,excellent carrier transport,high sensitivity,and cost-effective manufacturing.Meanwhile,perovskite based direct Xray imagers have been successfully demonstrated as well.In this review article,we firstly introduced some fundamental principles of direct X-ray detection and imaging,and summarized the advances of perovskite materials for these purposes and finally put forward some needful and feasible directions.
基金financially supported by the Natural Science Foundation of China(Grants 51972172,61705102,and 51802253)the China Postdoctoral Science Foundation(Grants 2021M692630)+6 种基金Natural Science Basic Research Plan in Shaanxi Province of China(2022JQ-629,2021JLM-43)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-007 and 2020GXLH-Z-014)Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(Grant BK20200034)the Innovation Project of Optics Valley Laboratory(OVL2021BG006)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2021WNLOKF003)the Young 1000 Talents Global Recruitment Program of Chinathe Fundamental Research Funds for the Central Universities.
文摘Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,modulation,to transmission)for next-generation optoelectronic technology.Notably,the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade,while in the next decade,it will be primarily critical to promote their implantation in the next-generation optoelectronics.In this review,we first retrospect the historical research milestones of MHPs and their optoelectronic devices.Thereafter,we introduce the origin of the unique optoelectronic features of MHPs,based on which we highlight the tunability of these features via regulating the phase,dimensionality,composition,and geometry of MHPs.Then,we show that owing to the convenient property control of MHPs,various optoelectronic devices with target performance can be designed.At last,we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems.This review demonstrates the key role of MHPs played in the development of modern optoelectronics,which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.
文摘A simple Cu（OAc）2 catalyzed Sonogashira coupling protocol is presented. It was found that the couplings of a variety of aryl halides with terminal alkynes were conducted smoothly to afford the corresponding desired products in moderate to excellent yields, using Cu（OAc）2 as the catalyst and Et3N as the solvent.
基金the National Natural Science Foundation of China (NSFC)/Research Grants Council (RGC) Joint Research project 51761165021 and N_CityU108/17 is gratefully acknowledged.
文摘We report an in-situ fabrication of halide perovskite (CH3NH3PbX3,CH3NH3 =methylammonium,MA,X =Cl,Br,I) nanocrystals in polyvinylalcohol (PVA) nanofibers (MAPbX3@PVA nanofibers) through electrospinning a perovskite precursor solution.With the content of the precursors increased,the resulting MAPbBr3 nanocrystals in PVA matrix changed the shape from ellipsoidal to pearl-like,and finely into rods-like.Optimized MAPbBr3@PVA nanofibers show strong polarized emission with the photoluminescence quantum yield of up to 72%.We reveal correlations between the shape of in-situ fabricated perovskite nanocrystals and the polarization degree of their emission by comparing experimental data from the single nanofiber measurements with theoretical calculations.Polarized emission of MAPbBr3@PVA nanofibers can be attributed to the dielectric confinement and quantum confinement effects.Moreover,nanofibers can be efficiently aligned by using parallel positioned conductor strips with an air gap as collector.A polarization ratio of 0.42 was achieved for the films of well-aligned MAPbBr3@PVA nanofibers with a macroscale size of 0.5 cm × 2 cm,which allows potential applications in displays,lasers,waveguides,etc.
