Investigation of the electronic band gap tuning by Si doping on BeO using UV–VIS spectroscopy and density functional theory

Abstract

BeO with tissue equivalent features promising dosimetric properties, making BeO particularly suitable for being used in all dosimetry applications. In this work, BeO was synthesized and doped with Si using sol-gel and solid-state methods, respectively. To find the optical band gap of Si-doped BeO nanoparticles (BeO:Si) experimentally, the ultraviolet-visible (UV–Vis) spectroscopy was used. To simulate the electronic band structure of BeO and Si-doped BeO, we used the QUANTUM ESPRESSO code based on density functional theory (DFT). The calculated electronic band structure exhibited insulator behavior and the band gap decreased with Si doping in two potential types. Compared to BeO, a shift toward lower energies was determined from the UV–Vis absorption spectrum of BeO:Si, the simulated and the experimental band gaps were found to be in good agreement. These findings offer insights into the dopant syntheses of BeO and their widespread use for fundamental studies as well as their potential applications.