Highly Efficient and Stable Solar Cells Based on Crystalline Oriented 2D/3D Hybrid Perovskite

• Published in: Advanced materials (Weinheim) 2019-08, Vol.31 (32), p.e1901242-n/a
• Main Authors: Zhou, Tong, Lai, Hongtao, Liu, Tingting, Lu, Di, Wan, Xiangjian, Zhang, Xiaodan, Liu, Yongsheng, Chen, Yongsheng
• Format: Article
• Language: English
• Subjects: Carrier lifetime; Carrier recombination; Cations; Crystal structure; Crystallinity; Energy conversion efficiency; Hybrid structures; Ion motion; Materials science; Perovskites; Photovoltaic cells; photovoltaics; Solar cells; spacer cations; stability
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201901242

Highly efficient and stable 2D/3D hybrid perovskite solar cells using 2‐thiophenemethylammonium (ThMA) as the spacer cation are successfully demonstrated. It is found that the incorporation of ThMA spacer cation into 3D perovskite, which forms a 2D/3D hybrid structure, can effectively induce the crystalline growth and orientation, passivate the trap states, and hinder the ion motion, resulting in improved carrier lifetime and reduced recombination losses. The optimized device exhibits a power conversion efficiency (PCE) of 21.49%, combined with a high VOC of 1.16 V and a notable fill factor (FF) of 81%. More importantly, an encapsulated 2D/3D hybrid perovskite device sustains ≈99% of its initial PCE after 1680 h in the ambient atmosphere, whereas the control 3D perovskite device drops to ≈80% of the original performance. Importantly, the device stability under continuous light soaking (100 mW cm−2) is enhanced significantly for 2D/3D perovskite device in comparison with that of the control device. These results reveal excellent photovoltaic properties and intrinsic stabilities of the 2D/3D hybrid perovskites using ThMA as the spacer cation. 2‐Thiophenemethylammonium spacer cations are successfully embedded into formamidinium iodide (FAI)‐ and methylammonium iodide (MAI)‐based 3D perovskites, and these cations can induce the crystalline growth and orientation of the obtained 2D/3D hybrid perovskite. A champion efficiency of 21.49% is demonstrated for a 2D/3D perovskite device, which is combined with a dramatically improved stability in comparison with that of the control device.