Spray deposition of vinyl tris(2-methoxyethoxy) silane-doped Ti3C2T MXene hole transporting layer for planar perovskite solar cells

Recently, coupling agents have gradually been applied to perovskite solar cells (PSC) due to their interface modification properties. In this work, Ti3C2Tx MXene nanosheets with different amounts of silane coupling agent vinyltris (2-methoxyethoxylsilane) (SCA) (0, 0.1, 0.3, 0.5, and 0.7 V/V%) were deposited by spray technique as the hole transport layer (HTL). Taking the advantage of SCA, the interface distribution of Ti3C2Tx after film formation is effectively modulated, while flat, pin-hole free Ti3C2Tx films were obtained with a mixing content of 0.3 V/V%. Superior hole transfer path, enhanced hole extraction, and reduced transfer resistance at the HTL/perovskite interface were achieved due to the better formation of Ti3C2Tx films, thus leading to an increase in power conversion efficiency (PCE) from 11.12% to 13.65%. This work represents an effective method to improve the quality of Ti3C2Tx-based films and provides more possibilities for future research on Ti3C2Tx MXene.