Diammonium‐induced<scp>Dion‐Jacobson 2D</scp>/<scp>3D</scp>wide‐bandgap perovskite solar cells with enhanced efficiency and stability
Yue Yu, Rui Liu, Maoxia Xu, Hua Yu
Abstract
Abstract Surface passivation by two‐dimensional (2D) organic spacers provides promising avenue to substantially enhance the photovoltaic performance and structural stability of perovskite solar cells (PSCs). Herein, a diammonium organic salt of 2,2′‐(Ethylenedioxy) diethyl ammonium diiodide (EDBEI 2 ) is used to passivate surface defects with spontaneously established Dion‐Jacobson (DJ)‐type two‐dimensional/three‐dimensional (2D/3D) perovskite structure. The 2D DJ perovskite (EDBEPbI 4 ) is formed on the surface of 3D WBG film, which passivates surface defects and reduces non‐radiation recombination with better‐matched energy‐level alignment. Consequently, the modified device shows an excellent power conversion efficiency of 18.85% with large open‐circuit voltage of 1.28 V. Besides, such 2D/3D perovskite exhibits better stability, which maintains 89% of its original efficiency after 1000 h under a relative humidity of 30% for the unencapsulated EDBEI 2 ‐treated device. These results give a suggestive strategy to enhance the efficiency and stability of WBG PSCs, potentially, providing a feasible way for achieving the commercialization of perovskites. image