Computational Investigation on Tunability of Optical Absorption in MoS2 Integrated with Mono- and Non-Alloyed AuAg Nanoparticles for Photodetector Application

Abstract

The optical properties of plasmonic materials, such as strong excitation and absorption, can indeed be manipulated by altering their structure, transitioning from mono- to bimetallic configurations, and integrating with 2D materials. The atomic thickness characteristic of 2D materials typically results in low light absorption. However, integrating plasmonic nanomaterials facilitates enhanced light-matter interactions. In our study, we investigate the tunability of optical absorption in gold (Au), silver (Ag), non-alloys of gold and silver (AuAg), and MoS₂ using the Finite Difference Time Domain (FDTD) method. We conduct detailed analyses of the influences of these configurations, considering variations in sizes and spacing. Our findings demonstrate that combining these materials results in tunable absorption peaks depending on the size and spacing of the particles; where the intensity of prominent peak at 600 nm increases for MoS₂-AuNPs and tuned to noticeable spectrum with percentage diameter of d = 125% has a different peak compared to the rest at around 550 nm for AgNPs, while of broader spectrum observed in 500–600-nm range for the diameter of D = 80 nm and D = 100 nm for bimetallic NPs. In summary, our research highlights the potential for manipulating the optical properties of plasmonic materials through structural modifications and integration with 2D materials, offering valuable insights for optimizing their performance in various applications especially in photodetector which we reported experimentally before.