Phase-Controlled Tin Selenide Photodetectors for Visible Blind to Near-Infrared Optical Radiation
Preeti Goswami, Pukhraj Prajapat, Pargam Vashishtha, Akhilesh Pandey, Govind Gupta
Abstract
Layered tin selenides have gained tremendous interest due to their distinct tunable semiconducting properties, narrow band gap, low cost, and feasibility for large-scale production. However, the phase controllability of SnSe and SnSe 2 is a major challenge for device applications, which should be addressed to ensure repeatability of crystallographic phase, morphology, defects, etc. We have synthesized highly crystalline and phase-controlled (mono, di, mix) tin selenide films using a low-pressure chemical vapor deposition technique by coupling the precursor and substrate temperatures. The optoelectronic behavior of the constructed metal–semiconductor–metal (MSM) tin selenide-based devices responds to the wide spectral range from visible blind (UVB) to near-infrared (NIR). The designed SnSe 2 -based photodetector has a high optical response to visible light (532 nm) with responsivity, noise equivalent power, and external quantum efficiency of 1260 mA W –1, 8.27 × 10 –12 W Hz –1/2, and 295%, respectively. However, the SnSe-based photodetector exhibits a high response for infrared wavelength (1064 nm) with responsivity, external quantum efficiency, and noise equivalent power of 3320 mA W –1, 388%, and 2.88 × 10 –12 W Hz –1/2, respectively. The SnSe-based photodetector outperforms the SnSe 2 and SnSe mix (mixed phase)-based devices in the optical wavelength range from UVB to NIR. A thorough analysis of a phase-controlled tin selenide photodetector with broad optical detecting capability indicates its adaptability to various industrial and technological domains.