Visible Light Detection through Optically Gated MoS2 Photosensor

Photodetectors are of utmost importance in optoelectronics and the rising multiplicity of technology calls for new materials and novel device paradigms. This work proposes an optically gated double-gate tunnel field-effect transistor photosensor, employing a monolayer of transition metal dichalcogenide as the channel material. The photodetector works on the principle of band-to-band tunneling, which, we demonstrate, is capable of detecting visible range of wavelength. The photogenerated voltage is developed upon illumination of light, and it has been modeled to illustrate the device’s operation. We discuss the effects of dielectric material and demonstrate the high value of photosensor parameters when a combination of HfO₂ and SiO₂ is used as dielectric materials in the photosensor. In addition, we explore the impact of the dimensions and positioning of the illumination window.