Yao Yuxin, Hang Pengjie, Wang Peng, Xu Lingbo, Cui Can, Xie Jiangsheng, Xiao Ke, Li Ge, Lin Ping, Liu Shuai, Xie Danyan, Che Siyuan, Yang Deren, Yu Xuegong
Center for Optoelectronics Materials and Devices, Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China.
Nanotechnology. 2019 Nov 8;31(8):085401. doi: 10.1088/1361-6528/ab55a1.
The performance of hybrid perovskite solar cells (PSCs) is significantly influenced by the crystallization and morphology of perovskite films. Herein, a novel method of CsPbBr quantum dots (QDs) assisted nucleation is applied to prepare high quality solution-processed methylammonium lead iodide (MAPbI) films by employing CsPbBr QDs as an additive into diethyl ether anti-solvent. The appropriate amount of CsPbBr QDs can act as effective heterogeneous nucleation centers, leading to the formation of smooth and pinhole-free perovskite films with increased grain size. Furthermore, the growth direction of MAPbI grains is regulated by CsPbBr QDs, exhibiting preferential orientation of (110) plane. Therefore, the MAPbI films with CsPbBr QDs modification show reduced defects and increased carrier lifetime. As a result, the champion PSC with a maximum power conversion efficiency (PCE) up to 20.17% is achieved and 85% of its initial PCE is maintained after aging 1000 h at room temperature under a relative humidity of 50%. This work demonstrates a feasible way to prepare high quality perovskite films for optoelectronic applications.
混合钙钛矿太阳能电池（PSC）的性能受到钙钛矿薄膜结晶和形貌的显著影响。在此，采用一种新型的CsPbBr量子点（QD）辅助成核方法，通过将CsPbBr量子点作为添加剂加入到乙醚反溶剂中，制备高质量的溶液法甲基碘化铅（MAPbI）薄膜。适量的CsPbBr量子点可作为有效的异质成核中心，导致形成具有更大晶粒尺寸的光滑且无针孔的钙钛矿薄膜。此外，CsPbBr量子点调节了MAPbI晶粒的生长方向，呈现出（110）面的择优取向。因此，经CsPbBr量子点修饰的MAPbI薄膜显示出缺陷减少且载流子寿命增加。结果，实现了最大功率转换效率（PCE）高达20.17%的最佳PSC，并且在50%相对湿度下于室温老化1000小时后仍保持其初始PCE的85%。这项工作展示了一种制备用于光电子应用的高质量钙钛矿薄膜的可行方法。
