Unraveling the relationship between the phenethylammonium-induced 2D phase on the perovskite surface and inverted wide bandgap perovskite solar cell performance

• Published in: Energy & environmental science 2024-11, Vol.17 (22), p.8658-8669
• Main Authors: Huo, Xiaomin, Mariotti, Silvia, Li, Yaoyao, Guo, Ting, Ding, Chenfeng, Ji, Penghui, Yuan, Shuai, Li, Tongtong, Meng, Ning, Liu, Xiaomin, Zhang, Jiahao, Rabehi, Ilhem Nadia, Zhang, Yu, Zhao, Suling, Wang, Hengyuan, Song, Dandan, Ono, Luis K, Xu, Zheng, Qi, Yabing
• Format: Article
• Language: English
• Subjects: Dipoles; Electron transport; Energy conversion efficiency; Energy gap; Energy levels; Heterojunctions; Open circuit voltage; Performance enhancement; Perovskites; Photovoltaic cells; Short circuit currents; Short-circuit current; Solar cells
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/d4ee02133a

Two- and three-dimensional (2D/3D) heterojunctions have been widely used to improve the performance of n-type/intrinsic/p-type (NIP) structured perovskite solar cells (PSCs). However, the electron blocking nature of the 2D ligands, such as phenethylammonium (PEA + ), on the perovskite surface is not conducive to PSCs with a p-type/intrinsic/n-type (PIN) structure. In this work, we improve the device performance by eliminating the 2D phase on the perovskite surface through the subsequent annealing process. After eliminating the 2D phase, a dipole layer forms with the remaining PEA + , resulting in an excellent energy level alignment between the perovskite and electron transport layer. As a result, the solar cells with the PIN structure using a 1.67 eV wide-bandgap triple-cation perovskite show an enhanced power conversion efficiency of 20.61% with a short circuit current density of 20.05 mA cm −2 and a fill factor of 81.57%. Furthermore, the open-circuit voltage ( V OC ) is improved from 1.20 V to 1.26 V, yielding a V OC deficit of 410 mV, which represents one of the lowest values among the PIN structured wide-bandgap PSCs. We studied the impact of phenethylammonium chloride on PIN-structured wide bandgap perovskite solar cells. Elimination of the 2D phase results in a champion efficiency of 20.61% and a V OC loss of only 410 mV with hysteresis-free J-V curves.