Presentation Information
[24p-22C-8]Trivalent cation doped SnO2 electron transport layer for the highly efficient perovskite solar cells
〇(DC)Shamim Ahmmed1,2, Yulu He1,2, Md. Emrul Kayesh1, Kiyoto Matsuishi2, Ashraful Islam1 (1.NIMS, 2.University of Tsukuba)
Keywords:
perovskite solar cell,electron transport layer
The rapid advancement of perovskite solar cells (PSCs), which reflected in their PCE rise from 3.8% to 26.1% in only 14 years, has garnered significant interest. The electron transport layer (ETL) for PSCs was first comprised of mesoporous titanium oxide (TiO2) coated over compact TiO2. Due to low electron-mobility and high-temperature annealing (500 °C) of TiO2, low temperature processable SnO2 with a wide band gap and high electron mobility has drawn interest as ETL for PSCs. However, the open circuit voltage (VOC) loss occurs in SnO2 ETL based PSCs due to high conduction band offset (CBO) at SnO2/perovskite interface and high interface defects at the SnO2/perovskite interface originating from the oxygen vacancy on the SnO2 surface. Duan et al. conducted a theoretical analysis of the p-type doping in SnO2 and reported that the p-type doping can shift the conduction band (CB) of the SnO2 to an upward energy level. In this research, a trivalent cation was introduced in SnO2 as a p-type dopant to overcome the limitations of the SnO2 ETL in the practical PSCs. The ultraviolet photoelectron spectroscopy (UPS) analysis revealed that the CB of SnO2 was shifted upward and closer to the CB of perovskite at the optimized doping concentration of the trivalent p-type dopant. Besides, the X-ray photoelectron spectroscopy (XPS) analysis confirmed the reduction of SnO2 surface oxygen vacancy after introduction of the doping element. As a result, the doped-SnO2 ETL-based PSCs exhibited a power conversion efficiency (PCE) of 22.25% with VOC of 1.16 V, while PCE of 20.52% with a VOC of 1.10 V was observed from the undoped SnO2-based PSCs.