Enhancing Spectral Responsivity of Zinc Oxide Nanoparticles via Laser Ablation on Porous Silicon

Abstract

In this research, the production of zinc oxide nanoparticles (ZnO NPs) was made using various pulsed laser ablation energy (PLA) embedded in substrates made up of porous silicon (PS). The PS substrates were created using the photoelectrochemical etching (PECE) technique of Si n-type (111). The research examined the impact of pulse laser ablation energy for some features on the prepared samples that involved the structural, electrical, optical, and morphological properties in photodetector application. XRD analysis reveals a broad diffraction peak at an angle of 28.4° for the porous silicon with other diffraction peaks at different angles, indicating the presence of the ZnO NPs phase corresponding to the structure of hexagonal wurtzite. The SEM image demonstrates that PS is sponge-like, while ZnO NPs display randomly dispersed spherical grains. The optical characteristics of the fabricated specimens were analyzed using photoluminescence and UV-vis absorption spectroscopy. It was observed that an increase in laser pulse energy results in a shift of the absorption wavelengths and a change in the energy gap. The J-V characteristics of the created specimens were analyzed under two conditions: in dark and light while varying the laser pulse energy. The photodetectors consisting of ZnO NPs/PS/n-Si exhibited rectifying characteristics and remarkable responsivity to a wide range of wavelengths, from UV to near-infrared. Furthermore, the constructed photodetectors exhibited enhanced quantum efficiency (Q.E), specifically in the ultraviolet (UV) range. The results of this research are significant in the progress of optoelectronic and photodetector devices that rely on ZnO NPs and PS.