Design and modeling of multi-color absorber based on periodic van der Waals heterostructures including TMDCs

Absorbers based on two-dimensional transition metal dichalcogenide (TMDC) heterostructures with direct band gap have recently attracted great research attention in optoelectronic applications. In this study, we design a multi-color absorber using a multilayer periodic arrangement of van der Waals heterostructures, including different TMDC thin layers (MoSe₂, MoS₂, WSe₂, and WS₂) on SiO₂ substrate. This newly emerging platform based on different compositions of TMDCs has been investigated to improve light absorption in the visible range. Multi-color detection can be achieved by combining distinct types of TMDCs with different layers. For instance, for two-color absorption, 3-layer-MoS₂ and 1-layer-WSe₂ have been located on the SiO₂ substrate alternatively to form a periodic heterostructure. In this case, the absorption spectrum illustrates two narrow peaks at 520 nm (green) and 700 nm (red) wavelengths. For three-color absorption, 3-layer-WSe₂ and 1-layer-WS₂ have been deposited on SiO₂ substrate alternatively, and the absorption spectrum displays three narrow peaks at 520 nm (green), 610 nm (orange), and 710 nm (red) wavelengths. Effects of the number of periods and the number of TMDC layers on the absorption spectrum have been investigated. As a result, the utilization of the periodic form of multilayer TMDCs demonstrates a high absorption peak of approximately 40% for distinct wavelengths within the visible range. This property can be employed in various optoelectronic devices and visible light communication.