Modifying the photoelectric performance of SnO2 via D-arginine monohydrochloride for high-performance perovskite solar cells

Although widely used as conducting substrates for solar cells, indium-tin oxide-based (ITO) electrodes’ potential for improvement of visible light transmittance is frequently overlooked of perovskite solar cells (PSCs) as most work focuses on the improvement of the working components (e.g., light absorber, etc) of the solar cells. This work shows a great improvement on solar cell performance by increasing the transmittance (up to 94 %) of the SnO2/ITO electrode through adjusting the refractive index of the SnO2 with D-arginine monohydrochloride (D-Arg) and introducing extra amino group, carboxyl groups and chloride ions to passivate interface defects. A 21.74 % of the championship power conversion efficiency is obtained, in comparison to the 19.58 % of the control device, and an increase in the short-circuit current from 23.26 to 24.51 mA cm−2. Long-term stability is demonstrated with more than 86 % retention rate of the initial when stored in an air environment (10 % −25 % RH, 25 ℃), for 720 h. Therefore, this work provides a new and general approach in improving the performance of PSCs.