Facile synthesis of hybrid nanorods with the Sb2Se3/AgSbSe2 heterojunction structure for high performance photodetectors

An effective colloidal process involving the hot-injection method is developed to synthesize uniform single-crystalline Sb2Se3 nanorods in high yields. The photoconductive characteristics of the assynthesized Sb2Se3 nanorods are investigated by developing a film-based photodetector and this device displays a remarkable response to visible light with an ON/OFF ratio as high as 50 (with an incident light density of 12.05 mW cm(-2)), short response/recovery times and long-term durability. To overcome the challenge of the intrinsic low electrical conductivity of Sb2Se3, hybrid nanorods with the Sb2Se3/AgSbSe2 heterojunction structure having a type-II band alignment are firstly prepared. The electric current of the photodetector based on the Sb2Se3/AgSbSe2 hybrid nanorod film has been significantly increased both in the dark and under light illumination. The responsivity of the photodetector based on the Sb2Se3/AgSbSe2 hybrid nanorod film is about 4.2 times as much as that of the photodetector based on the Sb2Se3 nanorod film. This improvement can be considered as an important step to promote Sb2Se3 based semiconductors for applications in high performance photodetectors.