Enhancing Performance of Perovskite Solar Cells: A Study on Passivating the Electron Transport Layer via Doctor-Blade Coating in Environmental Conditions

The stability and difficulty in the large-scale fabrication of perovskite solar cells have always affected their commercial development. In this study, we investigated a Nb5+-doped SnO2 electron transport layer to passivate surface defects. We fabricated perovskite solar cell devices using a full doctor-blade coating method and analyzed the effects of doping on the surface morphology, water contact angle, and device performance. The passivated SnO2 thin films showed a significant reduction in surface defects, improved electron transport, and a 2.3-fold enhancement in hydrophobicity, and its photovoltaic performance is maintained better than that of the freshly prepared undoped device after the device prepared under unencapsulated atmospheric conditions is placed for 1000 h. Due to its simple fabrication process, lower cost, and ease of large-scale preparation, it provides a feasible solution for the commercial development of perovskite solar cells.