Hu Long, Duan Leiping, Yao Yuchen, Chen Weijian, Zhou Zizhen, Cazorla Claudio, Lin Chun-Ho, Guan Xinwei, Geng Xun, Wang Fei, Wan Tao, Wu Shuying, Cheong Soshan, Tilley Richard D, Liu Shanqin, Yuan Jianyu, Chu Dewei, Wu Tom, Huang Shujuan
School of Engineering, Macquarie University Sustainable Energy Research Centre, Macquarie University, Sydney, NSW, 2109, Australia.
School of Materials Science and Engineering, University of New South Wales (UNSW), Sydney, NSW, 2052, Australia.
Adv Sci (Weinh). 2022 Jan;9(2):e2102258. doi: 10.1002/advs.202102258. Epub 2021 Nov 29.
Structural defects are ubiquitous for polycrystalline perovskite films, compromising device performance and stability. Herein, a universal method is developed to overcome this issue by incorporating halide perovskite quantum dots (QDs) into perovskite polycrystalline films. CsPbBr QDs are deposited on four types of halide perovskite films (CsPbBr , CsPbIBr , CsPbBrI , and MAPbI ) and the interactions are triggered by annealing. The ions in the CsPbBr QDs are released into the thin films to passivate defects, and concurrently the hydrophobic ligands of QDs self-assemble on the film surfaces and grain boundaries to reduce the defect density and enhance the film stability. For all QD-treated films, PL emission intensity and carrier lifetime are significantly improved, and surface morphology and composition uniformity are also optimized. Furthermore, after the QD treatment, light-induced phase segregation and degradation in mixed-halide perovskite films are suppressed, and the efficiency of mixed-halide CsPbIBr solar cells is remarkably improved to over 11% from 8.7%. Overall, this work provides a general approach to achieving high-quality halide perovskite films with suppressed phase segregation, reduced defects, and enhanced stability for optoelectronic applications.
多晶钙钛矿薄膜普遍存在结构缺陷，这会损害器件性能和稳定性。在此，通过将卤化物钙钛矿量子点（QDs）掺入钙钛矿多晶薄膜中，开发了一种通用方法来克服这一问题。CsPbBr量子点沉积在四种卤化物钙钛矿薄膜（CsPbBr 、CsPbIBr 、CsPbBrI 和MAPbI ）上，并通过退火触发相互作用。CsPbBr量子点中的离子释放到薄膜中以钝化缺陷，同时量子点的疏水配体在薄膜表面和晶界处自组装，以降低缺陷密度并提高薄膜稳定性。对于所有经量子点处理的薄膜，PL发射强度和载流子寿命都得到显著改善，表面形貌和成分均匀性也得到优化。此外，经过量子点处理后，混合卤化物钙钛矿薄膜中的光致相分离和降解受到抑制，混合卤化物CsPbIBr太阳能电池的效率从8.7%显著提高到超过11%。总体而言，这项工作提供了一种通用方法，以实现具有抑制相分离、减少缺陷和增强稳定性的高质量卤化物钙钛矿薄膜，用于光电子应用。
