Effective carrier transport tuning of CuO_x quantum dots hole interfacial layer for high-performance inverted perovskite solar cell

Interfacial layer is deemed as an efficient approach to align the energy level and reduce the carrier recombination at the interfaces. Therefore, for the first time, a facile yet effective method to enhance carrier transport by copper oxide quantum dots (CuO_x QDs) interfacial layer in inverted perovskite solar cells (PSCs) is developed. The high mobility of CuO_x QDs interfacial layer could boost the performance of PSCs by providing a better electrical carrier transport. Furthermore, the higher crystallinity of perovskite layer on CuO_x QDs layer reduced the charge trap state densities, which leads to an increase in carrier recombination resistance. As a result, our inverted PSCs exhibit a power conversion efficiency (PCE) of 19.91%, a 14.6% increment compared with the PCE of a control device. Our finding demonstrates the promise of enhancing carrier transport by interfacial layer for high-performance PSCs and expands choice of interfacial layer materials in PSCs.