Structural and Electrical Investigation of Porous Gaas Layers Prepared by Laser-Induced Etching Method

Gallium arsenide (GaAs) nanostructures are gaining prominence due to their exceptional optoelectronic properties and application potential in devices such as solar cells, LEDs, and transistors. While various fabrication techniques exist for creating GaAs nanostructures, laser-induced etching (LIE) offers a controllable and cost-effective method, particularly for producing porous GaAs layers with tunable morphologies. Despite earlier studies on LIE, there is limited exploration into the microstructural and electrical transformations induced by varying diode laser power densities, especially at 1050 nm wavelength, on (111)-oriented n-type GaAs substrates. This research aims to investigate the structural and electrical properties of porous GaAs layers formed via LIE using diode lasers at multiple power densities, and to evaluate their potential in electronic device fabrication. The AFM analysis revealed that increasing laser power from 0.5 to 9 W/cm² led to a systematic decrease in nanoparticle size (from ~15.73 nm to ~3.47 nm) and a corresponding increase in porous layer thickness (from 2 nm to 81.03 nm). Electrically, Al/porous-GaAs/n-GaAs/Al diodes exhibited enhanced rectification behavior with increasing laser power, attributed to carrier trap formation and heterojunction development. Ideality factors remained close to unity, indicating efficient charge transport. This study uniquely correlates laser power density with both the nanostructure morphology and diode performance, offering a refined understanding of LIE mechanisms. The findings provide practical guidance for tailoring porous GaAs layers for nanoelectronic and optoelectronic devices, and lay the groundwork for further exploration of diode-laser-based fabrication techniques.