Facile surface regulation for highly efficient and thermally stable perovskite solar cells via chlormequat chloride

• Published in: Chinese chemical letters Vol. 35; no. 10; pp. 109425 - 523
• Main Authors: Yang, Bo, Lin, Pu-An, Zhou, Tingwei, Zheng, Xiaojia, Cai, Bing, Zhang, Wen-Hua
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2024; Yunnan Key Laboratory of Carbon Neutrality and Green Low-carbon Technologies,School of Materials and Energy,Yunnan University,Kunming 650000,China%Yunnan Key Laboratory of Carbon Neutrality and Green Low-carbon Technologies,School of Materials and Energy,Yunnan University,Kunming 650000,China; Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621900,China%School of Physical Science and Technology,Southwest University,Chongqing 400715,China%Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621900,China
• Subjects: Chlormequat chloride; Perovskite solar cells; Quaternary ammonium halide; Surface modulation; Thermal stability; Chlormequat chloride; Surface modulation; Thermal stability; Perovskite solar cells; Quaternary ammonium halide
• ISSN: 1001-8417
• DOI: 10.1016/j.cclet.2023.109425

Defects at the surface and grain boundaries of the perovskite films are extremely detrimental to both the efficiency and stability of perovskite solar cells (PSCs). Herein, a simple and stable quaternary ammonium halide, named chlormequat chloride (i.e., chlorinated choline chloride, CCC), is introduced to regulate the upper surface chemical environment of perovskite films. The anion (Cl−) and cation [ClCH2CH2N(CH3)3]+ in CCC could effectively self-search and passivate positively and negatively charged ionic defects in perovskites, respectively, which contributes to inhibited nonradiative recombination and reduced energy loss in PSCs. As a result, the champion power conversion efficiency (PCE) of PSCs can be significantly enhanced from 22.82% to 24.07%. Moreover, the unencapsulated device with CCC modification retains 92.0% of its original PCE even subject to thermal aging at 85 °C for 2496 h. This work provides guidance for the rational design of functional molecules as defect passivators in PSCs, which is beneficial for the improvements in both device performance and stability. A quaternary ammonium halide without unstable hydroxyl group, named chlorinated choline chloride (CCC), is employed to modified the surface and grain boundaries of perovskite film, which passivates both positively and negatively charged ionic defects in perovskites, boosting the efficiency of perovskite solar cells from 22.82% to 24.07% with enhanced long-term stability. [Display omitted]