Nanocavity absorption enhancement for two-dimensional material monolayer systems

Abstract

Here we propose a strategy to enhance the light-matter interaction of two-dimensional (2D) material monolayers based on strong interference effect in planar nanocavities, and overcome the limitation between optical absorption and the atomically-thin thickness of 2D materials. By exploring the role of spacer layers with different thicknesses and refractive indices, we demonstrate that a nanocavity with an air spacer layer placed between a graphene monolayer and an aluminum reflector layer will enhance the exclusive absorption in the graphene monolayer effectively, which is particularly useful for the development of atomically-thin energy harvesting/conversion devices.

Single-crystalline germanium nanomembrane photodetectors on foreign nanocavities

“…Using single-crystalline semiconductor membranes on functionalized nanocavity substrates, we achieve strong light-matter interaction within nanometer-thick Ge films. Although we use Ge as an example to demonstrate a high-performance photodetector, our method can be applied to other semiconductors, including two-dimensional (2D) materials ( 22 , 23 ), to enable the development of improved ultrathin optical/optoelectronic devices.…”

Ultrathin‐Film Titania Photocatalyst on Nanocavity for CO2 Reduction with Boosted Catalytic Efficiencies

“…It is generally believed that significantly enhanced optical absorption within ultrathin films can overcome the long‐existing trade‐off between optical absorption and carrier transportation, which could revolutionize thin‐film energy harvesting and conversion applications (e.g., photocatalysis and photovoltaics). Recently, we proposed a lossless spacer in a three‐layered nanocavity structure to enhance the optical absorption within atomically thin semiconductor layers (e.g., in 1.5‐nm‐thick Ge films, and monolayers of graphene and MoS 2 ). A suitably designed lossless spacer layer was inserted between the bottom reflector and the top absorptive layers to optimize the disruptive interference condition and therefore enhance the optical absorption.…”

Engineering photonic environments for two-dimensional materials

“…To further enhance the light-matter interactions and release their excellent capabilities, 2D materials are integrated with nanocavities [38,39], metamaterials [40], metasurfaces [5], and even other 2D materials that can change the optical environments [41]. Integration of 2D materials with photonic circuits provides numerous advantages such as enhanced quantum yield (QY) [42][43][44][45], improved collection efficiency of emitted photons [46][47][48][49], easy routing and manipulation of optical signals [48,50], enhanced light-matter interaction [9,[51][52][53], and the formation of exciton-polaritons (EPs) states [54].…”