| 研究課題/領域番号 |
18F18370
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| 研究機関 | 電気通信大学 |
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研究代表者 |
沈 青 電気通信大学, 大学院情報理工学研究科, 教授 (50282926)
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| 研究分担者 |
LIU FENG 電気通信大学, 大学院情報理工学研究科, 外国人特別研究員
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| 研究期間 (年度) |
2018-11-09 – 2021-03-31
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| キーワード | perovskite nanocrystals / perovskite solar cell / near-unity PL QY |
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| 研究実績の概要 |
Trioctylphosphine (TOP)-based syntheses of CsPbI3 perovskite quantum dots (QDs) yield unprecedented high photoluminescence quantum yield (PLQY) of 100%, lower stokes shifts, and longer carrier lifetimes due to their enhanced crystallinity. This synthetic route relies on a heavily Pb-rich condition or a large Pb:Cs molar ratio in precursor solution to produce QDs with appropriate stoichiometry as well as to guarantee a good colloidal stability. The high Pb condition is achieved by a high concentration of PbI2 prepared in TOP. Here we find such Pb-rich strategies can be avoided by providing additional iodine ions using other metal halide salts. In particular GeI2, which contrary to PbI2, readily dissolves in TOP. CsPbI3 QDs prepared using PbI2/GeI2 combination show near-unity PL QY and improved chemical stability compared to the previous synthetic route. Furthermore we find no sign of Ge incorporation in the QDs (compositionally or energetically). The ensuing QD solar cells deliver power conversion efficiency of 12.15% and retain 85% of its peak performance after storage over 90 days. The PbI2/GeI2 dual-source iodine synthetic approach presented here represents a more rational and robust route to high-quality CsPbI3 QDs.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
The proposed study has been finished.
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| 今後の研究の推進方策 |
Alloyed Sn-Pb halide perovskites hold great potential for near-infrared applications due to their narrow band gaps and lower toxicity. However, Sn vacancy defect can be facilely generated due to its low formation energy, causing detrimental effects for the carrier transport and device efficiency. The plan of this study is to decrease Sn vacancies by doping strategy, which introduces impurities that can strongly modify optoelectronic properties of the materials.
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