Colloidal metal halide perovskite nanocrystals (NCs) have emerged as promising materials for optoelectronic devices and received considerable attention recently. Their superior photoluminescence (PL) properties provide significant advantages for lighting and display applications. In this Highlight, we discuss recent developments in the design and chemical synthesis of colloidal perovskite NCs, including both organic-inorganic hybrid and all inorganic perovskite NCs. We review the excellent PL properties and current optoelectronic applications of these perovskite NCs. In addition, critical challenges that currently limit the applicability of perovskite NCs are discussed, and prospects for future directions are proposed. ; Funding Agencies|Swedish Research Council (VR); Swedish Research Council (FORMAS); European Commission Marie Sklodowska-Curie actions; Carl Tryggers Stiftelse; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; China Scholarship Council
The development of perovskite emitters, their use in light-emitting devices, and the challenges in enhancing the efficiency and stability, as well as reducing the potential toxicity of this technology are discussed in this Review. Metal halide perovskites have shown promising optoelectronic properties suitable for light-emitting applications. The development of perovskite light-emitting diodes (PeLEDs) has progressed rapidly over the past several years, reaching high external quantum efficiencies of over 20%. In this Review, we focus on the key requirements for high-performance PeLEDs, highlight recent advances on materials and devices, and emphasize the importance of reliable characterization of PeLEDs. We discuss possible approaches to improve the performance of blue and red PeLEDs, increase the long-term operational stability and reduce toxicity hazards. We also provide an overview of the application space made possible by recent developments in high-efficiency PeLEDs. ; Funding Agencies|European Research Council Starting GrantEuropean Research Council (ERC) [717026]; Swedish Energy Agency EnergimyndighetenSwedish Energy Agency [48758-1]; Swedish Foundation for International Cooperation in Research and Higher Education [CH2018-7736]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; UK Engineering and Physical Sciences Research CouncilEngineering & Physical Sciences Research Council (EPSRC); Joint Research Program between China and the European Union [2016YFE0112000]; National Key Research and Development Program of China [2016YFB0401600]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [21975220, 91833303, 91733302, 51911530155]
The p-type characteristic of solution-processed metal halide perovskite transistors means that they could be used in combination with their n-type counterparts, such as indium-gallium-zinc-oxide transistors, to create complementary metal-oxide-semiconductor-like circuits. However, the performance and stability of perovskite-based transistors do not yet match their n-type counterparts, which limit their broader application. Here we report high-performance p-channel perovskite thin-film transistors based on inorganic caesium tin triiodide semiconducting layers that have moderate hole concentrations and high Hall mobilities. The perovskite channels are formed by engineering the film composition and crystallization process using a tin-fluoride-modified caesium-iodide-rich precursor with lead substitution. The optimized transistors exhibit field-effect hole mobilities of over 50 cm(2) V-1 s(-1) and on/off current ratios exceeding 10(8), as well as high operational stability and reproducibility. By optimizing the doping and crystallization behaviour of solution-processed metal halide perovskite thin films, p-channel transistors with mobilities of 50 cm(2) V-1 s(-1) and on/off ratios of 10(8) can be fabricated. ; Funding Agencies|Ministry of Science and ICT through the National Research Foundation - Korean government [2021R1A2C3005401, 2020R1A4A1019455, 2020M3F3A2A01085792, 2020M3D1A1110548, 2020R1A2C4001617]; Samsung Display CorporationSamsung
Photodetectors are critical parts of an optical communication system for achieving efficient photoelectronic conversion of signals, and the response speed directly determines the bandwidth of the whole system. Metal halide perovskites, an emerging class of low-cost solution-processed semiconductors, exhibiting strong optical absorption, low trap states, and high carrier mobility, are widely investigated in photodetection applications. Herein, through optimizing the device engineering and film quality, high-performance photodetectors based on all-inorganic cesium lead halide perovskite (CsPbIxBr3-x), which simultaneously possess high sensitivity and fast response, are demonstrated. The optimized devices processed from CsPbIBr2 perovskite show a practically measured detectable limit of about 21.5 pW cm(-2) and a fast response time of 20 ns, which are both among the highest reported device performance of perovskite-based photodetectors. Moreover, the photodetectors exhibit outstanding long-term environmental stability, with negligible degradation of the photoresponse property after 2000 h under ambient conditions. In addition, the resulting perovskite photodetector is successfully integrated into an optical communication system and its applications as an optical signal receiver on transmitting text and audio signals is demonstrated. The results suggest that all-inorganic metal halide perovskite-based photodetectors have great application potential for optical communication. ; Funding Agencies|National Natural Science Foundation of China [51472164, 61704077]; Shenzhen Peacock Plan [KQTD2016053112042971]; Educational Commission of Guangdong Province [2015KGJHZ006, 2016KCXTD006]; Science and Technology Planning Project of Guangdong Province [2016B050501005]; Natural Science Foundation of SZU [000050]; Natural Science Foundation of Jiangsu Province [BK20171007]; China Postdoctoral Science Foundation [2017M622744, 2018T110886, 2016M601784, 2017T100358]; Postdoctoral Science Foundation of Jiangsu Province [1701135B]; ERC Starting Grant [717026]; European Commission Marie Sklodowska-Curie Actions [691210]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; VINNMER Marie Curie Fellowships; 1000 Talents Program for Young Scientists of China
Colloidal metal oxide nanocrystals offer a unique combination of excellent low-temperature solution processability, rich and tuneable optoelectronic properties and intrinsic stability, which makes them an ideal class of materials as charge transporting layers in solution-processed light-emitting diodes and solar cells. Developing new material chemistry and custom-tailoring processing and properties of charge transporting layers based on oxide nanocrystals hold the key to boosting the efficiency and lifetime of all-solution-processed light-emitting diodes and solar cells, and thereby realizing an unprecedented generation of high-performance, low-cost, large-area and flexible optoelectronic devices. This review aims to bridge two research fields, chemistry of colloidal oxide nanocrystals and interfacial engineering of optoelectronic devices, focusing on the relationship between chemistry of colloidal oxide nanocrystals, processing and properties of charge transporting layers and device performance. Synthetic chemistry of colloidal oxide nanocrystals, ligand chemistry that may be applied to colloidal oxide nanocrystals and chemistry associated with post-deposition treatments are discussed to highlight the ability of optimizing processing and optoelectronic properties of charge transporting layers. Selected examples of solution-processed solar cells and light-emitting diodes with oxide-nanocrystal charge transporting layers are examined. The emphasis is placed on the correlation between the properties of oxide-nanocrystal charge transporting layers and device performance. Finally, three major challenges that need to be addressed in the future are outlined. We anticipate that this review will spur new material design and simulate new chemistry for colloidal oxide nanocrystals, leading to charge transporting layers and solution-processed optoelectronic devices beyond the state-of-the-art. ; Funding Agencies|National Key Research and Development Program of China [2016YFB0401602, 2016YFA0204000]; National Natural Science Foundation of China [51522209, 91433204, U1632118, 21571129]; Fundamental Research Funds for the Central Universities [2015FZA3005]; Shanghai Key Research program [16JC1402100]; Shanghai International Cooperation Project [16520720700]; Carl Tryggers Stiftelse; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linko "ping University [2009-00971]
Rational engineering of the surface properties of perovskite nanocrystals (PeNCs) is critical to obtain light emitters with simultaneous high photoluminescence efficiency and excellent charge transport properties for light-emitting diodes (LEDs). However, the commonly used lead halide sources make it hard to rationally optimize the surface compositions of the PeNCs. In addition, previously developed ligand engineering strategies for conventional inorganic nanocrystals easily deteriorate surface properties of the PeNCs, bringing additional difficulties in optimizing their optoelectronic properties. In this work, a novel strategy of employing a dual-purpose organic lead source for the synthesis of highly luminescent PeNCs with enhanced charge transport property is developed. Lead naphthenate (Pb(NA)(2)), of which the metal ions work as lead sources while the naphthenate can function as the surface ligands afterward, is explored and the obtained products under different synthesis conditions are comprehensively investigated. Monodispersed cesium lead bromide (CsPbBr3) with controllable size and excellent optical properties, showing superior photoluminescence quantum yields up to 80%, is obtained. Based on the simultaneously enhanced electrical properties of the Pb(NA)(2)-derived PeNCs, the resultant LEDs demonstrate a high peak external quantum efficiency of 8.44% and a superior maximum luminance of 31 759 cd cm(-2). ; Funding Agencies|National Key R&D Program of China [2017YFA0207400]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [61604032, 61905037]; Fundamental Research Funds for the Central Universities of ChinaFundamental Research Funds for the Central Universities [ZYGX2016J206]; "University of Electronic Science and Technology University Doctoral Academic Support Program" project; ERC Starting GrantEuropean Research Council (ERC) [717026]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFOMat-LiU) [2009-00971]
Ruddlesden-Popper perovskites (RPPs), consisting of alternating organic spacer layers and inorganic layers, have emerged as a promising alternative to 3D perovskites for both photovoltaic and light-emitting applications. The organic spacer layers provide a wide range of new possibilities to tune the properties and even provide new functionalities for RPPs. However, the preparation of state-of-the-art RPPs requires organic ammonium halides as the starting materials, which need to be ex situ synthesized. A novel approach to prepare high-quality RPP films through in situ formation of organic spacer cations from amines is presented. Compared with control devices fabricated from organic ammonium halides, this new approach results in similar (and even better) device performance for both solar cells and light-emitting diodes. High-quality RPP films are fabricated based on different types of amines, demonstrating the universality of the approach. This approach not only represents a new pathway to fabricate efficient devices based on RPPs, but also provides an effective method to screen new organic spacers with further improved performance. ; Funding Agencies|ERC Starting Grant [717026]; National Natural Science Foundation of China [51472164, 61704077]; 1000 Talents Program for Young Scientists of China; Shenzhen Peacock Plan [KQTD2016053112042971]; Educational Commission of Guangdong Province [2015KGJHZ006, 2016KCXTD006]; Science and Technology Planning Project of Guangdong Province [2016B050501005]; Natural Science Foundation of SZU [000050]; Joint NTU-LiU Ph.D. programme on Materials and Nanoscience; European Commission Marie Sklodowska-Curie Actions [691210]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFOMat-LiU) [2009-00971]; JSPS-NTU Joint Research Project [M4082176]; Ministry of Education Tier 2 [MOE 2017-T2-2-002]; Singapore National Research Foundation [NRF-CRP14-2014-03, NRF-NRFI-2018-04]
A robust and expedient gas quenching method is developed for the solution deposition of hybrid perovskite thin films. The method offers a reliable standard practice for the fabrication of a non-exhaustive variety of perovskites exhibiting excellent film morphology and commensurate high performance in both regular and inverted structured solar cell architectures. ; A.B. and M.T.K. contributed equally to this work. This work was financially supported by BOF (Hasselt University) and the Research Fund Flanders (FWO). B.C. is a postdoctoral research fellow of the FWO. A.B. was financially supported by Imec and FWO (grant V4.667.15N). M.T.K. acknowledges funding from the EPSRC project EP/M024881/1 "Organic-inorganic Perovskite Hybrid Tandem Solar Cells". S.B. is a VINNMER fellow and Marie Sklodowska-Curie fellow. J.V. and N.G. acknowledge funding from GOA project "Solarpaint" of the University of Antwerp and FWO project G.0044.13N "Charge ordering". The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The authors thank Johnny Baccus and Jan Mertens for technical support.
Despite rapid improvements in efficiency and brightness of perovskite light-emitting diodes (PeLEDs), the poor operational stability remains a critical challenge hindering their practical applications. Here, we demonstrate greatly improved operational stability of high-efficiency PeLEDs, enabled by incorporating dicarboxylic acids into the precursor for perovskite depositions. We reveal that the dicarboxylic acids efficiently eliminate reactive organic ingredients in perovskite emissive layers through an in situ amidation process, which is catalyzed by the alkaline zinc oxide substrate. The formed stable amides prohibit detrimental reactions between the perovskites and the charge injection layer underneath, stabilizing the perovskites and the interfacial contacts and ensuring the excellent operational stability of the resulting PeLEDs. Through rationally optimizing the amidation reaction in the perovskite emissive layers, we achieve efficient PeLEDs with a peak external quantum efficiency of 18.6% and a long half-life time of 682 h at 20 mA cm(-2), presenting an important breakthrough in PeLEDs. ; Funding Agencies|ERC Starting grantEuropean Research Council (ERC) [717026]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; China Scholarship Council (CSC)China Scholarship Council
Lead-free halide double perovskites with diverse electronic structures and optical responses, as well as superior material stability show great promise for a range of optoelectronic applications. However, their large bandgaps limit their applications in the visible light range such as solar cells. In this work, an efficient temperature-derived bandgap modulation, that is, an exotic fully reversible thermochromism in both single crystals and thin films of Cs2AgBiBr6 double perovskites is demonstrated. Along with the thermochromism, temperature-dependent changes in the bond lengths of Ag Symbol of the Klingon Empire Br (R-Ag Symbol of the Klingon Empire Br) and Bi Symbol of the Klingon Empire Br (R-Bi Symbol of the Klingon Empire Br) are observed. The first-principle molecular dynamics simulations reveal substantial anharmonic fluctuations of the R-Ag Symbol of the Klingon Empire Br and R-Bi Symbol of the Klingon Empire Br at high temperatures. The synergy of anharmonic fluctuations and associated electron-phonon coupling, and the peculiar spin-orbit coupling effect, is responsible for the thermochromism. In addition, the intrinsic bandgap of Cs2AgBiBr6 shows negligible changes after repeated heating/cooling cycles under ambient conditions, indicating excellent thermal and environmental stability. This work demonstrates a stable thermochromic lead-free double perovskite that has great potential in the applications of smart windows and temperature sensors. Moreover, the findings on the structure modulation-induced bandgap narrowing of Cs2AgBiBr6 provide new insights for the further development of optoelectronic devices based on the lead-free halide double perovskites. ; Funding Agencies|Knut and Alice Wallenberg Foundation; National Natural Science Foundation of China [61704078, 61722403]; Natural Science Foundation of Jiangsu Province of China [BK20160990]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [200900971]; European Commission Marie Skodowska-Curie actions [691210]; European Commission SOLAR-ERA.NET; Swedish Energy Agency (Energimyndigheten); Swedish Research Council (FORMAS); China Scholarship Council; Recruitment Program of Global Youth Experts in China; National Key Research and Development Program of China [2016YFB0201204]; Program for JLU Science and Technology Innovative Research Team; Swedish Research Council (VR) [2014-4750]; Ministry of Education and Science of the Russian Federation [074-02-2018-327]
Solution-processed metal halide perovskites (MHPs) have demonstrated great advances on achieving high-performance photodetectors. However, the intrinsic material instability and the toxicity of lead still hinder the practical applications of MHPs-based photodetectors. In this work, the first highly sensitive and fast-response lead-free perovskite photodetectors based on Cs2AgBiBr6 double perovskite films are demonstrated. A convenient solution method is developed to deposit high-quality Cs2AgBiBr6 film with large grain sizes, low trap densities, and long charge carrier lifetimes. Incorporated within a photodiode device architecture comprised of optimized hole- and electron-transporting layers, lead-free perovskite photodetectors are achieved exhibiting a high detectivity of 3.29 x 10(12) Jones, a large linear dynamic range of 193 dB, and a fast response time of approximate to 17 ns. All the key figures of merit of the devices are comparable with the reported best-performing photodetectors based on lead halide perovskites. In addition, the resulting devices exhibit excellent thermal and environmental stability. The nonencapsulated devices show negligible degradation after thermal stressing at 150 degrees C and less than 5% degradation in the photoresponsivity after storage in ambient air for approximate to 2300 h. The results demonstrate the great potential of the lead-free Cs2AgBiBr6 double perovskite in applications for environmentally friendly and high-performance photodetectors. ; Funding Agencies|National Natural Science Foundation of China [51472164]; 1000 Talents Program for Young Scientists of China, Shenzhen Peacock Plan [KQTD2016053112042971]; Educational Commission of Guangdong Province [2015KGJHZ006, 2016KCXTD006]; Science and Technology Planning Project of Guangdong Province [2016B050501005]; China Postdoctoral Science Foundation [2017M622744, 2018T110886]; Swedish Research Council FORMAS [942-2015-1253]; European Commission Marie Sklodowska-Curie Actions [691210]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]
The preparation of highly efficient perovskite nanocrystal light-emitting diodes is shown. A new trimethylaluminum vapor-based crosslinking method to render the nanocrystal films insoluble is applied. The resulting near-complete nanocrystal film coverage, coupled with the natural confinement of injected charges within the perovskite crystals, facilitates electron-hole capture and give rise to a remarkable electroluminescence yield of 5.7%. ; This work was supported by the EPSRC [Grant numbers EP/M005143/1, EP/J017361/1 and EP/G037221/1]. G.L. thanks Gates Cambridge Trust for funding. F.W.R.R. is grateful for financial support from CNPq [Grant number 246050/2012-8]. N.J.L.K.D. thanks the Cambridge Commonwealth European and International Trust, Cambridge Australian Scholarships and Mr Charles K. Allen for financial support. F.W.R.R., F.D.P. and C.D. acknowledge funding from the ERC under grant number 259619 PHOTO-EM. C.D. acknowledges financial support from the EU under grant number 312483 ESTEEM2. F.G. acknowledges financial support from the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University. ; This is the final version of the article. It first appeared from Wiley via https://doi.org/10.1002/adma.201600064
Despite the impressive development of metal halide perovskites in diverse optoelectronics, progress on high-performance transistors employing state-of-the-art perovskite channels has been limited due to ion migration and large organic spacer isolation. Herein, we report high-performance hysteresis-free p-channel perovskite thin-film transistors (TFTs) based on methylammonium tin iodide (MASnI(3)) and rationalise the effects of halide (I/Br/Cl) anion engineering on film quality improvement and tin/iodine vacancy suppression, realising high hole mobilities of 20 cm(2) V-1 s(-1), current on/off ratios exceeding 10(7), and threshold voltages of 0 V along with high operational stabilities and reproducibilities. We reveal ion migration has a negligible contribution to the hysteresis of Sn-based perovskite TFTs; instead, minority carrier trapping is the primary cause. Finally, we integrate the perovskite TFTs with commercialised n-channel indium gallium zinc oxide TFTs on a single chip to construct high-gain complementary inverters, facilitating the development of halide perovskite semiconductors for printable electronics and circuits. Progress on high-performance transistor employing perovskite channels has been limited to date. Here, Zhu et al. report hysteresis-free tin-based perovskite thin-film transistors with high hole mobility of 20 cm(2)V(-1)S(-1), which can be integrated with commercial metal oxide transistors on a single chip. ; Funding Agencies|Ministry of Science and ICT through the National Research Foundation - Korean government [2021R1A2C3005401, 2020R1A4A1019455]; Samsung Display CorporationSamsung
Solar cells based on metal halide perovskites are one of the most promising photovoltaic technologies(1-4). Over the past few years, the long-term operational stability of such devices has been greatly improved by tuning the composition of the perovskites(5-9), optimizing the interfaces within the device structures(10-13), and using new encapsulation techniques(14,15). However, further improvements are required in order to deliver a longer-lasting technology. Ion migration in the perovskite active layer-especially under illumination and heat-is arguably the most difficult aspect to mitigate(16-18). Here we incorporate ionic liquids into the perovskite film and thence into positive-intrinsic-negative photovoltaic devices, increasing the device efficiency and markedly improving the long-term device stability. Specifically, we observe a degradation in performance of only around five per cent for the most stable encapsulated device under continuous simulated full-spectrum sunlight for more than 1,800 hours at 70 to 75 degrees Celsius, and estimate that the time required for the device to drop to eighty per cent of its peak performance is about 5,200 hours. Our demonstration of long-term operational, stable solar cells under intense conditions is a key step towards a reliable perovskite photovoltaic technology. ; Funding Agencies|UK Engineering and Physical Sciences Research Council (EPSRC) [EP/M015254/2, EP/M024881/1]; European Research Council (ERC) [717026]; Swedish Research Council Vetenskapsradet [330-2014-6433]; European Commission Marie Sklodowska-Curie action [INCA 600398]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [SFO-Mat-LiU 2009-00971]; European Union [763977]; China Scholarship Council (CSC); Bavarian State Ministry of Science, Research, and the Arts; German Research Foundation (DFG); Swiss National Science Foundation [cr23i2-162828]
The preparation of highly efficient perovskite nanocrystal light-emitting diodes is shown. A new trimethylaluminum vapor-based crosslinking method to render the nanocrystal films insoluble is applied. The resulting near-complete nanocrystal film coverage, coupled with the natural confinement of injected charges within the perovskite crystals, facilitates electron-hole capture and give rise to a remarkable electroluminescence yield of 5.7%. ; Funding Agencies|EPSRC [EP/M005143/1, EP/J017361/1, EP/G037221/1]; Gates Cambridge Trust; CNPq [246050/2012-8]; ERC [259619 PHOTO-EM]; EU [312483 ESTEEM2]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [200900971]; Cambridge Commonwealth European and International Trust; Cambridge Australian Scholarships
