Simultaneously enhanced performance and stability of inverted perovskite solar cells via a rational design of hole transport layer

Interface engineering is of critical importance to achieve high performance perovskite solar cells. Herein, a readily-prepared and sustainable hole transport layer (HTL) based on the poly(3,4-ethylenedioxy-thiophene):sulfonated acetone-formaldehyde (PEDEO:SAF) as an alternative of poly(3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) is reported to efficiently improve the film electrical properties, enhance the charge transfer and extraction, and finally enhance the efficiency and stability of inverted perovskite solar cells. Compared with PEDOT:PSS HTL, PEDOT:SAF HTL possesses higher film conductivity, and less acidity, leading to much improved ambient stability of devices. This work suggests that PEDOT:SAF HTL could be an efficient HTL for high performance and stable perovskite solar cells.