Broadband and Broad-Angle Optical Absorption by MoS2 and MoSe2 Monolayers in 1D Photonic Crystals

Transition metal dichalcogenides (TMDCs) hold great potential for various applications in the fields of photonics and optoelectronics. Different real-life applications require high, broadband, and broad-angle optical absorption by photonic devices. TMDC materials such as monolayer MoS₂ and monolayer MoSe₂ showcase high amount of absorption in the visible wavelength range. This paper focuses on the analysis of optical absorption by MoS₂ and MoSe₂ monolayers in one-dimensional photonic crystals. Absorption spectra for different 1D photonic crystal structures involving MgF₂ and PMMA are calculated using the transfer matrix method (TMM). The effects of number of periods and incident angle are also taken into consideration. It is observed that large number of periods leads to high broadband optical absorption with greater than 90% maximum value in the 400-700 nm wavelength range. Broad-angle absorption averaging above 70% for large incident angles having values up to 70 degrees is also obtained.