The Optical Band Gap Based on K-M Function on Layer of LiTaO3 with Variation Treatment of Annealing Temperature

Abstract

The thin layer made from the material of LiTaO3 on a P-type silicon wafer has been produced by using Chemical Solution Deposition (CSD) technique. In this study, the thin films have been annealed with thermal differences in the furnace (Nabertherm B410) for 15 hours at a temperature of 75$0^{o}$C, 80$0^{o}$C, and 85$0^{o}$C. The reflectance data related to the characteristic of thin films have been measured by using deuterium-halogen light sources (Ocean Optics DH-2000-BAL) and spectrometer (Ocean Optics USB4000-UV-VIS) in the wavelength that ranges between 230-850 nm. The K-M (Kubelka-Munk) function is applied to estimate the optical band gap value referred to the reflectance data and photon energy. The result of this study shows that the optical band gap of LiTaO3 material on P-type silicon wafers are having a sensitivity shift in accordance with the increment of temperature. Based on the result of optical band gap values related to light spectrum, it is concluded that the thin films have the potential to be applied as a sensor with sensitivity to the ultraviolet and visible region.