Optical properties of β-Ga2O3 nanorods synthesized by a simple and cost-effective method using egg white solution

In this paper, we report on the optical properties of gallium oxide (beta-Ga2O3) nanorods synthesized by a simple, cost-effective and environment-friendly method using gallium(III) nitrate hydrate and freshly extracted egg white (ovalbumin) in an aqueous medium. The extracted egg white acted as a matrix for the entrapment of gallium ions to generate a gelled precursor. The structure of the prepared samples was studied by X-ray diffraction and Raman spectroscopy to confirm the formation of beta-Ga2O3 with a monoclinic structure after calcination of the precursor in air at 750, 850, and 950 degrees C for 3 h. Scanning electron microscopy images revealed the morphology and formation of nanorods with different sizes and shapes in the samples, resulting from the effect of the calcination temperature. All the samples showed a strong UV absorption with the band gap in the range of 3.87-3.97 eV. Room-temperature photoluminescence spectra of all the samples also showed a strong UV emission. The UV emission results were discussed based on the basis of charge recombination. (C) 2015 The Japan Society of Applied Physics