Polarity and moisture induced trans-grain-boundaries 2D/3D coupling structure for flexible perovskite solar cells with high mechanical reliability and efficiency. Issue 12 (26th October 2022)

• Record Type: Journal Article
• Authors: Yan, Ying; Wang, Ruiting; Dong, Qingshun; Yin, Yanfeng; Zhang, Linghui; Su, Zhenhuang; Wang, Chenyue; Feng, Jiangshan; Wang, Minhuan; Liu, Jing; Ma, Hongru; Feng, Yulin; Shang, Wenzhe; Wang, Zhiyong; Pei, Mingzhu; Wang, Yudi; Jin, Shengye; Bian, Jiming; Gao, Xingyu; Liu, Shengzhong; Shi, Yantao
• Is Part Of: Energy & environmental science. Volume 15:Issue 12(2022)
• Page Start: 5168
• Page End: 5180
• Publication Date: 2022-10-26
• Subjects: Energy conversion -- Periodicals; Fuel switching -- Periodicals; Environmental sciences -- Periodicals; Environmental chemistry -- Periodicals; 333.79
• DOI: 10.1039/d2ee01879a
• Languages: English
• ISSNs: 1754-5692

Abstract

Abstract : Precise control of the growth of 2D perovskites on 3D perovskites to form "trans-grain boundaries" 2D/3D structure for the preparation of flexible perovskite solar cells with a certified PCE up to 22.1% and excellent mechanical stability. Abstract : To commercialize flexible perovskite solar cells (f-PSCs), they must achieve mechanical reliability along with high power conversion efficiency (PCE) and long-term stability. 2D/3D stacking of perovskites can theoretically improve the photovoltaic performance and mechanical reliability of f-PSCs simultaneously. But due to the complexity of the surface reaction, it remains a significant challenge to precisely control the growth of 2D perovskites with favorable growth sites, morphologies, and mechanical properties on 3D perovskites. Here we report the polarity of X -bromobenzylamine ( X = 2, 3, and 4) salts as well as ambient moisture to be critical factors governing the reaction selectivity and growth behavior of 2D perovskites on 3D perovskites. The mild polarity-induced reaction selectivity, namely 4-bromobenzylamine cations with PbI2, enables precise growth of 2D perovskites at the grain boundaries (GBs) of 3D perovskites, while moderate moisture further stimulates the growth of 2D perovskites to form a trans-GBs structure. This unique "trans-GBs" 2D perovskite forms a p – n heterojunction with 3D perovskites, enhancing the built-in potential and exhibiting an excellent passivation effect and suitable mechanical properties (with the Young's modulus comparable to that of 3D MHP). As a result, the trans-GBs 2D/3D based f-PSCs obtained a certified PCE of up to 22.1% and maintained ∼80% of their initial PCE after 8000 bending cycles ( R = 4 mm).