Kong Wenchi, Zhao Chen, Huang Tao, Li Xiuyun, Xing Jun, Yu Zhi, Yang Peng, Li Wei, Yu Weili
GPL Photonics Laboratory, State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, P. R. China.
University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
ACS Appl Mater Interfaces. 2022 Jun 22;14(24):28154-28162. doi: 10.1021/acsami.2c02427. Epub 2022 Jun 10.
The instability of perovskite optoelectronic devices remains a big barrier to their commercialization. The instability caused by external stimuli has been addressed by encapsulation, such as humidity, oxygen, heat, and ultraviolet light. However, the intrinsic instability of perovskite materials due to the lattice strain has not been fully addressed, which affects the physical properties and device performance to a great extent. Tuning the lattice strain by controlling the perovskite composition and ratio is an effective way to further develop efficient and stable devices. Herein, we prepare a series of triple-cation and mixed-halide (FAPbI)(MAPbBr)(CsPbI) perovskite single-crystal thin films and study the effect of lattice strain on the perovskite optoelectronic properties. Especially, the perovskite photodetector with a horizontal structure based on (FAPbI)(MAPbBr)(CsPbI) single-crystal thin films exhibits excellent performance with an enhanced responsivity of 40 A/W, high detectivity of 1.9 × 10 Jones, external quantum efficiency of 9100%, and superior stability. This can be explained by the fact that the optimal coordination between each element leads to the release of lattice strain and further produces low defect density and long carrier lifetime in (FAPbI)(MAPbBr)(CsPbI) single-crystal thin films. This research shows the significance of ion ratios in tuning lattice strain and determining the intrinsic device performance and makes the perovskite (FAPbI)(MAPbBr)(CsPbI) a promising candidate for the next generation of optoelectronic devices.
钙钛矿光电器件的不稳定性仍然是其商业化的一大障碍。由外部刺激引起的不稳定性已通过封装来解决，如湿度、氧气、热量和紫外线。然而，由于晶格应变导致的钙钛矿材料的固有不稳定性尚未得到充分解决，这在很大程度上影响了物理性能和器件性能。通过控制钙钛矿的组成和比例来调节晶格应变是进一步开发高效稳定器件的有效方法。在此，我们制备了一系列三阳离子和混合卤化物（FAPbI）（MAPbBr）（CsPbI）钙钛矿单晶薄膜，并研究了晶格应变对钙钛矿光电性能的影响。特别是，基于（FAPbI）（MAPbBr）（CsPbI）单晶薄膜的水平结构钙钛矿光电探测器表现出优异的性能，响应率提高到40 A/W，探测率高达1.9×10琼斯，外量子效率为9100%，且具有卓越的稳定性。这可以解释为，各元素之间的最佳配位导致晶格应变的释放，并进一步在（FAPbI）（MAPbBr）（CsPbI）单晶薄膜中产生低缺陷密度和长载流子寿命。这项研究表明了离子比例在调节晶格应变和决定器件固有性能方面的重要性，并使钙钛矿（FAPbI）（MAPbBr）（CsPbI）成为下一代光电器件的有前途的候选材料。
