Enhanced electron extraction using neodymium ions doped TiO2 for all-inorganic CsPbBr3 perovskite solar cells
Tianyu Gao, Haojie Sui, Jingwei Zhu, Haiyan Chen, Qunwei Tang, Benlin He
Abstract
The high-quality electron-transport layer (ETL) plays a vital role in boosting the power conversion efficient (PCE) of perovskite solar cells (PSCs). Herein, the lanthanide neodymium (Nd) is used as a dopant to incorporate into the lattice of TiO 2 to reduce the trap states and form a n-doping effect, resulting in an increase in electron mobility and conductivity of TiO 2 , an energy level of TiO 2 matching well with that of the perovskite layer. Moreover, the improved wettability of the Nd-TiO 2 film enables a fabrication of perovskite light-absorbing layer with high-quality. As a result, the all-inorganic CsPbBr 3 PSCs based on Nd-TiO 2 ETL achieve a champion PCE of 10.06% owing to the promotion of charge extraction and the inhibition of charge recombination, which is a significantly improved efficiency in comparison with the 6.57% value of the reference cell. Additionally, the target device without encapsulation displays an effectively enhanced stability with over 90% and 80% retention of the original efficiency after aging in ambient air with high humidity (80% RH, 25 °C) for 30 days and under AM 1.5 G illumination at 85 °C for 100 h, respectively.