Enhance interaction between light and 2D material

Abstract

Two-dimensional materials, such as MoS₂, have attracted significant attention for their potential in optoelectronics, photodetectors, and quantum devices due to their unique optical and electronic properties. However, their atomic-level thickness imposes inherent limitations on their optical modulation depth. The weak interaction between light and these ultrathin materials often makes it challenging to achieve a strong optical response, with many devices facing constraints such as insufficient interaction depth, high optical losses, or the need for low-temperature operation, limiting their practical applications. This study addresses these challenges by employing a meticulously designed optical cavity featuring a highly reflective metal substrate and an optimally tuned spacer layer thickness. The cavity design significantly enhances the excitonic interactions in MoS₂. For single-layer MoS₂, the cavity achieves a 20% increase in absorption at room temperature, demonstrating its effectiveness in amplifying light-matter interactions. For bilayer MoS₂, the reflection spectrum not only reveals stronger excitonic interactions at the A and B excitons but also distinctly displays the interlayer excitons between the two peaks— phenomena typically challenging to observe under normal conditions. The cavity enhances the local electromagnetic field intensity, making the interlayer excitonic response more pronounced in bilayer structures. This work establishes a versatile platform for enhancing light-matter interactions in two-dimensional materials using cavity effects. It provides a robust experimental framework for studying complex excitonic dynamics, such as interlayer excitons in bilayer TMDs, under ambient conditions. Furthermore, the study lays a foundation for developing advanced optoelectronic and quantum devices, exploring the strong coupling between exciton states and cavity modes, and advancing the understanding of photonics and quantum phenomena in 2D materials. The findings contribute to the development of high performance optoelectronic systems and pave the way for the next generation of photonics and quantum technologies.