Physical Investigations of In2O3/Porous Silicon at Different Laser Wavelengths

Abstract

In this study, In2O3 thin films deposited on porous silicon using the pulsed laser deposition (PLD) method. The PSi substrate was prepared by photo electrochemical etching with the diode laser assistant. The impacts of various laser wavelengths on structural, spectroscopic, and performance characterizations were investigated. XRD revealed that the In2O3/PSi films have a polycrystalline cubic structure. The PL test showed measurements of two emission peaks related to In2O3 films (500, 463, 460 nm) and the PSi membrane (857, 852, 829 nm). The peaks at shorter wavelengths increased the energy gap from 2.4 eV to 2.69 eV. AFM results showed the surface roughness of the prepared samples were (3.78, 2.74, 2.3 nm), respectively and the root mean square (4.47, 3.26, 3.12 nm), respectively. FESEM images illustrated that the prepared samples had an average diameter size of (34.51, 25.55, 29.44 nm) with a cauliflower-like shape at 355 nm and rod-shaped particles for both 532 and 1064 nm. EDX tests were performed to figure out the elemental composition of In2O3/PSi the concentrations. The longer the laser wavelength, the higher the concentration of indium. The highest laser wavelength increased the transmission while decreasing the absorption.