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1دورية أكاديمية
المؤلفون: Jiaxin Pan, Ziming Chen, Tiankai Zhang, Beier Hu, Haoqing Ning, Zhu Meng, Ziyu Su, Davide Nodari, Weidong Xu, Ganghong Min, Mengyun Chen, Xianjie Liu, Nicola Gasparini, Saif A. Haque, Piers R. F. Barnes, Feng Gao, Artem A. Bakulin
المصدر: Nature Communications, Vol 14, Iss 1, Pp 1-10 (2023)
مصطلحات موضوعية: Science
الوصف: Abstract Conventional spectroscopies are not sufficiently selective to comprehensively understand the behaviour of trapped carriers in perovskite solar cells, particularly under their working conditions. Here we use infrared optical activation spectroscopy (i.e., pump-push-photocurrent), to observe the properties and real-time dynamics of trapped carriers within operando perovskite solar cells. We compare behaviour differences of trapped holes in pristine and surface-passivated FA0.99Cs0.01PbI3 devices using a combination of quasi-steady-state and nanosecond time-resolved pump-push-photocurrent, as well as kinetic and drift-diffusion models. We find a two-step trap-filling process: the rapid filling (~10 ns) of low-density traps in the bulk of perovskite, followed by the slower filling (~100 ns) of high-density traps at the perovskite/hole transport material interface. Surface passivation by n-octylammonium iodide dramatically reduces the number of trap states (~50 times), improving the device performance substantially. Moreover, the activation energy (~280 meV) of the dominant hole traps remains similar with and without surface passivation.
وصف الملف: electronic resource
Relation: https://doaj.org/toc/2041-1723
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2دورية أكاديمية
المؤلفون: Mingzhu Long, Tiankai Zhang, Yang Chai, Chun-Fai Ng, Thomas C. W. Mak, Jianbin Xu, Keyou Yan
المصدر: Nature Communications, Vol 7, Iss 1, Pp 1-11 (2016)
مصطلحات موضوعية: Science
الوصف: The stability of perovskite thin films and devices depends on a number of environmental factors, amongst which humidity. Here, Longet al. develop a synthetic route using a nonstoichiometric acid-base reaction to prepare films stable in humid environments for two months.
وصف الملف: electronic resource
Relation: https://doaj.org/toc/2041-1723
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3دورية أكاديمية
المؤلفون: Jiajia Suo, Bowen Yang, Edoardo Mosconi, Dmitry Bogachuk, Tiarnan A. S. Doherty, Kyle Frohna, Dominik J. Kubicki, Fan Fu, YeonJu Kim, Oussama Er-Raji, Tiankai Zhang, Lorenzo Baldinelli, Lu
المصدر: Nature, Nature Energy. 9(2):172-183
الوصف: The stabilization of grain boundaries and surfaces of the perovskite layer is critical to extend the durability of perovskite solar cells. Here we introduced a sulfonium-based molecule, dimethylphenethylsulfonium iodide (DMPESI), for the post-deposition treatment of formamidinium lead iodide perovskite films. The treated films show improved stability upon light soaking and remains in the black α phase after two years ageing under ambient condition without encapsulation. The DMPESI-treated perovskite solar cells show less than 1% performance loss after more than 4,500 h at maximum power point tracking, yielding a theoretical T80 of over nine years under continuous 1-sun illumination. The solar cells also display less than 5% power conversion efficiency drops under various ageing conditions, including 100 thermal cycles between 25 °C and 85 °C and an 1,050-h damp heat test.
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4دورية أكاديمية
المؤلفون: Tao Meng, Tiankai Zhang, Mengyuan Chen, Jiang Cao
المصدر: John Wiley & Sons, Ltd., Managerial and Decision Economics. 45(2):578-589
الوصف: This paper synthesizes the differences in the predictive power of multidimensional firm characteristics on organizational resilience and further identifies the key characteristics and their specific impact patterns. It is found that the firm's stability during the crisis depends more on the pre‐crisis firm's operating conditions, while the post‐crisis firm's flexibility depends more on the firm's internal and external resources. Besides, some firm characteristics rank higher in predicting the importance of organizational resilience. This study examines organizational resilience characteristics from a more comprehensive perspective and provides empirical evidence on how managers can better respond to systemic crises and enhance organizational resilience.
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المؤلفون: Tiankai Zhang, Feng Wang, Hak-Beom Kim, In-Woo Choi, Chuanfei Wang, Eunkyung Cho, Rafal Konefal, Yuttapoom Puttisong, Kosuke Terado, Libor Kobera, Mengyun Chen, Mei Yang, Sai Bai, Bowen Yang, Jiajia Suo, Shih-Chi Yang, Xianjie Liu, Fan Fu, Hiroyuki Yoshida, Weimin M. Chen, Jiri Brus, Veaceslav Coropceanu, Anders Hagfeldt, Jean-Luc Brédas, Mats Fahlman, Dong Suk Kim, Zhangjun Hu, Feng Gao
المصدر: Science. 377:495-501
مصطلحات موضوعية: Multidisciplinary, transport, voltage, impact, interlayers, p-dopant, stability, organic semiconductors, oxygen, performance, states
الوصف: Record power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) have been obtained with the organic hole transporter 2,2′,7,7′-tetrakis( N , N -di- p -methoxyphenyl-amine)9,9′-spirobifluorene (spiro-OMeTAD). Conventional doping of spiro-OMeTAD with hygroscopic lithium salts and volatile 4- tert -butylpyridine is a time-consuming process and also leads to poor device stability. We developed a new doping strategy for spiro-OMeTAD that avoids post-oxidation by using stable organic radicals as the dopant and ionic salts as the doping modulator (referred to as ion-modulated radical doping). We achieved PCEs of >25% and much-improved device stability under harsh conditions. The radicals provide hole polarons that instantly increase the conductivity and work function (WF), and ionic salts further modulate the WF by affecting the energetics of the hole polarons. This organic semiconductor doping strategy, which decouples conductivity and WF tunability, could inspire further optimization in other optoelectronic devices.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::39e11c5b197bfc5657d00f665c180e22
https://doi.org/10.1126/science.abo2757 -
6From optical pumping to electrical pumping: the threshold overestimation in metal halide perovskites
المؤلفون: Jiajun Qin, Yang Tang, Jia Zhang, Tangyao Shen, Max Karlsson, Tiankai Zhang, Weidong Cai, Lei Shi, Wei-Xin Ni, Feng Gao
مصطلحات موضوعية: Mechanics of Materials, Process Chemistry and Technology, Teoretisk kemi, General Materials Science, Electrical and Electronic Engineering, Theoretical Chemistry
الوصف: The threshold carrier density, conventionally evaluated from optical pumping, is a key reference parameter towards electrically pumped lasers with the widely acknowledged assumption that optically excited charge carriers relax to the band edge through an ultrafast process. However, the characteristically slow carrier cooling in perovskites challenges this assumption. Here, we investigate the optical pumping of state-of-the-art bromide- and iodine-based perovskites. We find that the threshold decreases by one order of magnitude with decreasing excitation energy from 3.10 eV to 2.48 eV for methylammonium lead bromide perovskite (MAPbBr(3)), indicating that the low-energy photon excitation facilitates faster cooling and hence enables efficient carrier accumulation for population inversion. Our results are then interpreted due to the coupling of phonon scattering in connection with the band structure of perovskites. This effect is further verified in the two-photon pumping process, where the carriers relax to the band edge with a smaller difference in phonon momentum that speeds up the carrier cooling process. Furthermore, by extrapolating the optical pumping threshold to the band edge excitation as an analog of the electrical carrier injection to the perovskite, we obtain a critical threshold carrier density of similar to 1.9 x 10(17) cm(-3), which is one order of magnitude lower than that estimated from the conventional approach. Our work thus highlights the feasibility of metal halide perovskites for electrically pumped lasers. Funding Agencies|ERC Consolidator Grant [101045098]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]; China National Key Basic Research Program [2022YFA1404800]; National Science Foundation of China [12234007, 12221004, 91963212]; Science and Technology Commission of Shanghai Municipality [19XD1434600, 2019SHZDZX01, 19DZ225 3000, 20501110500, 21DZ1101500]; Marie Curie Fellowship [Horizon-MSCA-2021-PF, 101066960]; Horizon Europe
وصف الملف: application/pdf
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0abf50c40a40cd6433d209538889447d
http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-192187 -
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المؤلفون: Tiankai Zhang, Feng Wang, Feng Gao
المصدر: Proceedings of the MATSUS23 & Sustainable Technology Forum València (STECH23).
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::d1671d0621cfa52ab26490108d4405d5
https://doi.org/10.29363/nanoge.matsus.2023.173 -
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المؤلفون: Jibin, Zhang, Tiankai, Zhang, Zhuangzhuang, Ma, Fanglong, Yuan, Xin, Zhou, Heyong, Wang, Zhe, Liu, Jian, Qing, Hongting, Chen, Xinjian, Li, Shijian, Su, Jianing, Xie, Zhifeng, Shi, Lintao, Hou, Chongxin, Shan
المصدر: Advanced materials (Deerfield Beach, Fla.).
الوصف: All-inorganic perovskite nanocrystals (NCs) are promising candidates for light-emitting diodes (LEDs) owing to their excellent optoelectronic properties. However, the pure-red perovskite LEDs (PeLEDs) available today made from mixed-halide CsPb(Br/I)
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المؤلفون: Zhenye Zhan, Dongxu Lin, Juntao Cai, Yueheng Lu, Aidi Chen, Tiankai Zhang, Ke Chen, Pengyi Liu, Xiaomu Wang, Weiguang Xie
المصدر: Advanced materials (Deerfield Beach, Fla.).
مصطلحات موضوعية: Mechanics of Materials, Mechanical Engineering, General Materials Science
الوصف: With the development of perovskite photodetectors, integrating photodetectors into array image sensors is the next target to pursue. The major obstacle to integrating perovskite photodiodes for dynamic imaging is the optoelectrical crosstalk among the pixels. Herein, a perovskite photodiode-blocking diode (PIN-BD) crossbar array with pixel-wise rectifying property by the vapor deposition method is presented. The PIN-BD shows a large rectification ratio of 3.3 × 10
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المؤلفون: Lingxiang Pan, Kwanho Ngai, Jian Chen, Jianbin Xu, Fangyan Xie, Minchao Qin, Mingzhu Long, Tiankai Zhang, Xinhui Lu
المصدر: Science Bulletin. 65:1832-1839
مصطلحات موضوعية: Multidisciplinary, Photoluminescence, Materials science, Auger effect, Passivation, business.industry, Quantum yield, 010502 geochemistry & geophysics, 01 natural sciences, law.invention, symbols.namesake, law, symbols, Optoelectronics, Quantum efficiency, business, Current density, 0105 earth and related environmental sciences, Perovskite (structure), Light-emitting diode
الوصف: Metal halide perovskite light emitting diodes (PeLEDs) have recently experienced rapid development due to the tunable emission wavelengths, narrow emission linewidth and low material cost. To achieve state-of-the-art performance, the high photoluminescence quantum yield (PLQY) of the active emission layer, the balanced charge injection, and the optimized optical extraction should be considered simultaneously. Multiple chemical passivation strategies have been provided as controllable and efficient methods to improve the PLQY of the perovskite layer. However, high luminance under large injection current and high external quantum efficiency (EQE) can hardly be achieved due to Auger recombination at high carrier density. Here, we decreased the electron injection barrier by tuning the Fermi-level of the perovskite, leading to a reduced turn on voltage. Through molecular doping of the hole injection material, a more balanced hole injection was achieved. At last, a device with modified charge injection realizes high luminance and quantum efficiency simultaneously. The best device exhibits luminance of 55,000 cd m−2, EQE of 8.02% at the working voltage of 2.65 V, current density of 115 mA cm−2, and shows EQE T50 stability around 160 min at 100 mA cm−2 injection current density.
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