High-efficiency planar heterojunction perovskite solar cell produced by using 4-morpholine ethane sulfonic acid sodium salt doped SnO2

Perovskite solar cells (PSCs) have become a promising photovoltaic (PV) technology. Meanwhile, developing an electron transport layer (ETL) has been an effective way to promote the power conversion efficiency (PCE) of PSCs. Here, a 4-morpholine ethane sulfonic acid sodium salt (MES Na + ) doped SnO 2 ETL is utilized in planar heterojunction PSCs. The results show that the MES Na + doped ETL can improve the crystallinity , and absorbance of perovskite films, and passivate interface defects between the perovskite film and SnO 2 ETL. The doping effect accounts for the enhancement of conductivity and the decreasing work function of SnO 2 . When 10 mg mL −1 MES Na + was added to the SnO 2 precursor solution, the device showed the best performance Jsc, Voc, and FF of the PSCs values, which were 23.88 mA cm −2 , 1.12 V and 78.69%, respectively, and the PCE was increased from 17.43% to 21.05%. This doping ETL strategy provides an avenue for defect passivation to further increase the efficiency of perovskite solar cells.