Photoresponse of Optical Sensors Based on Transition Metal Dichalcogenides: Influence of Thickness on Spectral Characteristics

Prototype field-effect transistors based on solid solutions of transition metal dichalcogenides (TMDs) have been manufactured, and their spectral characteristics were studied using the photocurrent spectroscopy technique. Results of theoretical estimation of the total optical absorbance of two-dimensional (2D) TMD-based semiconductors of various thicknesses are presented as dependent on the light wavelength with allowance for the multiray interference. It is established that the interference effect significantly contributes to the resulting shapes of spectral characteristics of these optical sensors with variable thickness of TMD-based photosensitive layers.