Degradation of band-gap photoluminescence in GaAs

Abstract

Evidence is presented to show that the degradation of near-band-gap photoluminescence emission in GaAs with time of exposure to low power, cw laser excitation can be attributed to a surface mechanism that is independent of surface oxidation and may involve an interaction between crystal point defects and the photogenerated electron-hole plasma near the surface.

Observing visible-range photoluminescence in GaAs nanowires modified by laser irradiation

“…It is known that the rate of photostimulated reaction in GaAs reduces greatly with temperature lowering. 23,24 To verify this tendency, we measure the sequence of PL spectra shown in Fig. 2(c).…”

Recombination Kinetics and Effects of Superacid Treatment in Sulfur- and Selenium-Based Transition Metal Dichalcogenides

“…Unlike conventional 3D materials, where terminations in the crystal lattice result in dangling bonds, ideal 2D systems have natural out-of-plane self-termination. As a result, it could be expected that monolayer semiconductors should show near-unity PL QY, whereas materials such as GaAs require cladding layers (i.e., AlGaAs) to show similar performance. , However, due to the presence of defects, the QY in 2D materials has typically been quite poor . Fortunately, monolayer semiconductors also offer a unique opportunity for defect passivation/repair because there is no distinction between bulk and surface defects, as such the entire semiconductor can be accessed.…”

High Luminescence Efficiency in MoS2 Grown by Chemical Vapor Deposition

“…22 In GaAs, double-heterostructures (using an AlGaAs cladding layer) are utilized to create a virtual defect-free interface. 23,24 Similarly, interfacial passivation is a requirement for 2D materials, which is partially mediated due to the natural selftermination of the 2D lattice at the surface, resulting in no dangling bonds. However, the quality of the surface is still severely degraded by the presence of defects.…”