Optics and Photonics Society of Iran

Two dimensional transition metal dichalcogenide (TMDC) layers with direct band gap have opened new research horizon for application in photonics and optoelectronics. WSe₂ monolayer from TMDCs family shows interesting optical properties. In this paper, we applied the Lorentz model to determine the permittivity of single WSe₂ layer in visible and infrared range and found good agreement with those of experimental results. The absorption of the structure is similar to imaginary component of the single WSe₂ layer and absorption peaks are found to be coincidence with Lorentz resonance wavelength. We furthermore investigate the absorption of single WSe₂ layer on different substrates which is commonly used in experiments. It is found that the substrate has an important role to reduce the absorption and absorption decreases with increasing the refractive index of substrate. Our results can be useful to design optoelectronic devices designed based on TMDCs.