Eco‐Friendly Solvent Engineered CsPbI2.77Br0.23 Ink for Large‐Area and Scalable High Performance Perovskite Solar Cells

• Published in: Advanced materials (Weinheim) Vol. 36; no. 11
• Main Authors: Abate, Seid Yimer, Qi, Yifang, Zhang, Qiqi, Jha, Surabhi, Zhang, Haixin, Ma, Guorong, Gu, Xiaodan, Wang, Kun, Patton, Derek, Dai, Qilin
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 14-03-2024
• Subjects: Acetonitrile; all‐inorganic perovskite; binary and ternary solvent; Dimethyl sulfoxide; eco‐friendly solvent; Energy conversion efficiency; Jet printing; Low temperature; Perovskites; Photovoltaic cells; Relative humidity; Shearing; Size distribution; slot‐die coating; Solar cells; solvent engineering; Solvents; Sulfoxides
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202310279

The performance of large‐area perovskite solar cells (PSCs) has been assessed for typical compositions, such as methylammonium lead iodide (MAPbI3), using a blade coater, slot‐die coater, solution shearing, ink‐jet printing, and thermal evaporation. However, the fabrication of large‐area all‐inorganic perovskite films is not well developed. This study develops, for the first time, an eco‐friendly solvent engineered all‐inorganic perovskite ink of dimethyl sulfoxide (DMSO) as a main solvent with the addition of acetonitrile (ACN), 2‐methoxyethanol (2‐ME), or a mixture of ACN and 2‐ME to fabricate large‐area CsPbI2.77Br0.23 films with slot‐die coater at low temperatures (40–50 °C). The perovskite phase, morphology, defect density, and optoelectrical properties of prepared with different solvent ratios are thoroughly examined and they are correlated with their respective colloidal size distribution and solar cell performance. The optimized slot‐die‐coated CsPbI2.77Br0.23 perovskite film, which is prepared from the eco‐friendly binary solvents dimethyl sulfoxide:acetonitrile (0.8:0.2 v/v), demonstrates an impressive power conversion efficiency (PCE) of 19.05%. Moreover, the device maintains ≈91% of its original PCE after 1 month at 20% relative humidity in the dark. It is believed that this study will accelerate the reliable manufacturing of perovskite devices.
CsPbI2.77I0.23 slot‐die inks are developed via the colloidal engineering of scalable large‐area perovskite solar cells. Eco‐friendly solvents such as dimethyl sulfoxide, acetonitrile, and 2‐methoxyethanol are used. Film growth is controlled by varying the solvent ratio. The cells based on films prepared by slot‐die coating exhibit an efficiency of 19.05%.