Experimental Verification of Size Dependence of Intrinsic Bandgap of ZnO Nanoparticles

This research paper presents experimental evidence demonstrating the relationship between the size of ZnO nanoparticles and their electrical bandgap (Eg), The authors employed the precipitation method to synthesize ZnO nanoparticles of varying sizes, and the intrinsic bandgap for each size was determined through UV-visible absorption spectra analysis. By combining the energy of light equation with the Lambert-Beer law, the square of the absorption value obtained from the spectra was found to be directly proportional to the energy of the incident light. The intrinsic bandgap of the material was then obtained by determining the x-intercept of the tangent at the steep section of the square of amplitude - energy plot. The experimental results revealed that the bandgap of ZnO nanoparticles increased as their size decreased. Additionally, the experimentally determined intrinsic bandgap values were compared with the numerically calculated values for further analysis.