Graded interface engineering of 3D/2D halide perovskite solar cells through ultrathin (PEA)2PbI4 nanosheets

• 作者: Lijie Zhu Qipeng Lu Chunhai Li Yue Wang Zhenbo Deng
• 来源期刊: 中国化学快报（英文版）
• 年，卷（期）: 2021,（7）
• 所属期刊栏目: Communications
• 页码范围: 2259-2262
• 页数: 4页
• 语种: 英文

摘要

2D halide perovskites have emerged as promising materials because of their stability and passivation effect in perovskite solar cells (PSCs). However, the introduction of bulky organic ammonium cations from 2D halide perovskites would decrease the device performance generally compared to the traditional 3D MAPbI3. Incorporation of ultrathin 2D halide perovskite nanosheets (NSs) with 3D MAPbI3 could address this issue. Herein, we report a rationally designed PSCs with dimensional graded 3D/2D MAPbI3/(PEA)2PbI4 heterojunction, in which 2D (PEA)2PbI4 NSs were synthesized and incorporated between 3D MAPbI3 and hole-transporting layer. Besides the significantly improved stability, a notable increasement in power conversion efficiency (PCE) of 20％was obtained for the 3D/2D perovskite solar cells due to the favourable band alignment among (PEA)2PbI4 NSs and the other components. The graded structure of MAPbI3/(PEA)2PbI4 would upshift the energy level continuously, which enhances the hole extraction efficiency thus reduces the interface charge recombination, leading to the increasements of VOC from 1.04 V to 1.07 V, JSC from 21.81 mA/cm2 to 23.15 mA/cm2 and the fill factor from 67.89％to 74.78％, and therefore an overall PCE of 18.53％.