Solution-processed GeSe/CdS heterogenous film for self-powered photodetectors

Two-dimensional (2D) materials display excellent photoelectric behaviors which makes them promising candidates for photodetectors and related fields. Germanium selenide (GeSe), as an advanced photosensitive 2D material, owns remarkable photo absorption and fast carrier mobility. However, its photo-electron conversion efficiency suffers from high carrier recombination. Building heterojunctions is one effective strategy to facilitate the separation efficiency of photoinduced electron-hole. Here, hybridization of GeSe and CdS is realized and prepared by assembling CdS nanodots on the electrodeposited GeSe film in an ethanol solution, to form a p-n type heterogeneous film on the ITO substrate. A PEC-type photodetector is fabricated based on the GeSe/CdS heterogeneous film, which displays obviously strengthened photocurrent density and photoresponsivity. Meanwhile, such GeSe/CdS PEC photodetector exhibits the capability of self-powered photoresponse and good stability. This heterogeneous structure paves an accessible and practical way for promoting GeSe hybrids toward high-efficient photoelectric conversion devices.