Copper(I)
thiocyanate (CuSCN) is a wide bandgap and solution-processable p-type semiconductor with tremendous potential for large-area
optoelectronic applications. In this work, chlorine-doped CuSCN (Cl2–CuSCN) was utilized to form a hole transport layer
(HTL) for different organic solar cells (OSCs) and inverted perovskite
solar cells (PSCs). Chlorine doping into CuSCN thin films is found
to improve the device performance of different OSCs, to a level comparable
to that of PEDOT:PSS-based OSCs. Notably, the inverted PSCs with Cl2–CuSCN showed a better performance than those with
pristine CuSCN or PEDOT:PSS-based inverted PSC devices. Moreover,
Cl2–CuSCN-based OSCs and PSCs also reveal significantly
better stability than pristine CuSCN and PEDOT:PSS-based devices.
Our results show how Cl2–CuSCN thin films act as
a universally applicable HTL for emerging solar cell technologies,
improving both device performance and stability.