2D MoS2 Encapsulated Silicon Nanopillar Array with High-Performance Light Trapping Obtained by Direct CVD Process

Abstract

Weak absorption remains a vital factor that limits the application of two-dimensional (2D) materials due to the atomic thickness of those materials. In this work, a direct chemical vapor deposition (CVD) process was applied to achieve 2D MoS2 encapsulation onto the silicon nanopillar array substrate (NPAS). Single-layer 2D MoS2 monocrystal sheets were obtained, and the percentage of the encapsulated surface of NPAS was up to 80%. The reflection and transmittance of incident light of our 2D MoS2-encapsulated silicon substrate within visible to shortwave infrared were significantly reduced compared with the counterpart planar silicon substrate, leading to effective light trapping in NPAS. The proposed method provides a method of conformal deposition upon NPAS that combines the advantages of both 2D MoS2 and its substrate. Furthermore, the method is feasible and low-cost, providing a promising process for high-performance optoelectronic device development.

High Quantum Efficiency and Broadband Photodetector Based on Graphene/Silicon Nanometer Truncated Cone Arrays

“…Within the wavelength range of 400-1100 nm, the micro-structured silicon substrates (silicon nanopillars and Si NTCAs) showed significant light-trapping properties, leading to a reflection of less than 40% for most wavelengths. Compared with silicon nanopillars as discussed in the early work of other researchers [5,18], the Si NTCAs substrate in this work showed a better light trapping effect, with an antireflection improvement of up to 30% in the wavelength range of 400-1100 nm. Figure 5b shows the measured reflection values of the three different substrates, and these values are consistent with the simulation results.…”

Planar Optical Cavities Hybridized with Low‐Dimensional Light‐Emitting Materials

“…Despite its accuracy, deterministic transfer is only suitable for lab‐scale sample preparation, and not for large‐scale and high‐throughput fabrication. The feasible solution for the large‐area process is direct growth on top of optical cavities using CVD, [ 203,204 ] which has the merit of requiring no extra steps. This one‐step method enables the fabrication of compact integrated structures that can enhance optical properties [ 204 ] and make defects of 2D materials according to nucleation sites.…”