Effect of nitrogen ion implantation on the structural and optical properties of indium oxide thin films

Abstract

: We report here synthesis and subsequent nitrogen ion implantation of indium oxide (In2O3) thin films. The films were implanted with 25keV N+ beam for different ion doses between 3E15 to 1E16 ions/cm2. The resulting changes in structural and optical properties were investigated using XRD, SEM-EDAX and UV-Vis Spectrometry. XRD studies reveal decrease in crystallite size from 20.06 to 12.42 nm with increase in ion dose. SEM micrographs show an increase in the grain size from 0.8 to 1.35 µm with increase in ion dose because of the agglomeration of the grains. Also, from EDAX data on pristine and N-implanted thin films the presence of indium and oxygen without any traces of impurity elements could be seen. However, at lower ion doses such as 3E15 and 5E15 ions/cm2, no evidence of the presence of nitrogen ion was seen. However, for the ion dose of 1E16 ions/cm2, evidence of presence of nitrogen can be seen in the EDAX data. Band gap calculations reveal a decrease in band gap from 3.54 to 3.38eV with increasing ion dose. However, the band gap was found to again show an increase to 3.58eV at the highest ion dose owing to quantum confinement effect.