Highly responsive, low -bias operated SnSe 2 nanostructured thin film for trap -assisted NIR photodetector

Photo detectors are very important for operation of various opto-electronic devices, like night vision camera, thermal imaging, remote sensing and so on. As the sizes of devices are shrinking day by day, it is important to make photo detectors which are small, robust, stable and have good responsitivity. Also the materials should be made from earth abundant elements and can be deposited using simple deposition techniques. Recently, good photo-detection capabilities in the infrared as well as visible range have been reported in metal dichalcogenides (WSe2,MoSe2,SnSe2,SnS2,WS2,MoS2,PtSe2,PdSe2 etc). SnSe2 is made of earth abundant elements. In this study, we report IR photo response in SnSe2 nanostructured thin films grown on soda lime glass (SLG) by thermal evaporation technique. IR (1064 nm) photo response behavior of the film is measured at different bias voltages in 100–400 mV range in steps of 100 mV and laser power density of 30–79 mW/cm2. The responsitivity of the device shows non-saturation of the traps states in the device. The value of responsitivity was 0.796± 0.003 mA/W (standard deviation) at 79 mW/cm2 laser power density and 400 mV bias voltage and the rise/decay times were 276 ms/332 ms, respectively. It is to be noted that the photo response behavior of film was stable and reproducible even after keeping them in atmospheric conditions for many months. This shows the potential of SnSe2 as a suitable material for various opto-electronic applications. To the best of our knowledge, the present study shows superior values of responstivity and response/recovery time of SnSe2 thin film on SLG substrate. © 2020 Elsevier B.V.