INVESTIGATION OF OPTICAL PROPERTIES OF X-RAY IRRADIATED GaSe THIN FILMS GROWN BY ELECTRODEPOSITION

The optical properties of X-ray irradiated GaSe thin films grown at electrolytic bath temperatures of 60 and 80oC have been studied in
this work. The results for the as-deposited GaSe revealed the films grown at 60 and 80oC have energy band gaps of 2.80 and 2.20 eV
respectively. The absorption/extinction coefficients of the deposited materials were found to be 3.72 × 104 cm-1 and 4.44 × 104 cm-1 /
0.12 and 0.15 respectively. The films were later exposed to X-ray for ~10 seconds. Upon exposure of the films to X-ray radiation, the energy band gaps of the samples increased to 3.00 and 2.35 eV, the absorption coefficients of the GaSe thin films decreased to 3.52 × 104 cm-1 and 3.97 × 104 cm-1 respectively, for the films grown at 60 and 80oC. The elimination of the noise effects at the ultra-violet region of the absorption spectrum of the investigated samples was noticed after X-ray irradiation. Thus, X-ray irradiation could serve as a post-deposition treatment of thin films.