MoS2 based photosensor detecting both light wavelength and intensity

MoS2 is a typical two-dimensional transition-metal dichalcogenide material, which has been researched intensively in the past few years. It is believed to hold promises in sensing and optical applications because of its intriguing electrical and optical properties. In this report, we have fabricated a MoS2 based photosensor which can detect both light wavelength and intensity. Firstly, the characteristics of MoS2 device under light irradiation and corresponding photoluminescence are measured at air ambient. Two mechanisms, carrier generation and gas desorption, are found to contribute to the drain current of MoS2 device under light irradiation. Following that, measurements of MoS2 device under different light irradiation and gas adsorption conditions are carried out to understand their relationship. Based on the relationship between gas desorption and photoresponse, it is revealed that the photoresponse has a strong dependence on its intensity and wavelength, which enables a photosensor capable of detecting both light intensity and wavelength.