Stability enhancement of perovskite solar cells via multi-point ultraviolet-curing-based protection

Abstract

As efficiency approaches the limit, it becomes more urgent to solve the toxicity and instability of organometal halide perovskite solar cells (PSCs), which asks for enhancement by applying methods that majorly contribute to stability itself to help prevent device from suffering from harmful matters. In this paper, we introduce a simple ultraviolet (UV) curing recipe which contains ethoxylated trimethylolpropane triacrylate (ETPTA) and 2-hydroxy-2-methyl-1-phenyl-1-propanone. ETPTA is polymerized by UV-curing and is applied as additive rather than as encapsulation material to distribute around the perovskite as a cross-linked network. Suitable amount of UV-gel added in perovskite precursor solution and hole transport material solution during device fabrication could promotes the crystallization of perovskite, reduce the diffusion of moisture in hole transport layer and therefore avoid degradation of PSCs. Notable protection happens with a volume percentage of ETPTA no more than 0.5%, especially in ambient conditions with humidity larger than 60%. • UV-gel is introduced through fabrication process and polymerized by UV-curing. • The addition of UV-gel is beneficial to the crystallization of perovskite. • Polymerized UV-gel effectively prevents the degradation of perovskite and device.