Engineering NiO Thin Film Properties using Ag9+ Ion Irradiation at Various Fluences

Abstract

The impact of the Ag9+ ion irradiation on the characteristics of nickel oxide (NiO) films with several ion fluences including 1 × 1012, 1 × 1013 and 1 × 1014 ions cm−2 has been studied. These films were deposited over fluorine-doped tin oxide (FTO) substrate via spin coating technique. After that, structural, optical, vibrational, and electrical characteristics of all films were investigated employing different techniques. The change in the structure due to Ag9+ ion has been studied by GIXRD technique. A slight improvement in crystalline nature of NiO thin film was observed at 1 × 1012 ions cm−2 ion fluence that can be understood via thermal spike model. A decrement in value of transmission has been observed in the case of all thin films with ion fluence of Ag9+ ion. In addition, it was also observed that samples exposed to Ag9+ ions resulted in reduced intensity of the 1LO and 2LO modes in Raman spectrum. The reduced intensity of the Raman modes indicates the increment in the lattice defects. Further, AFM analysis showed that increment in the ion fluences of incident Ag9+ on NiO thin films led to an enhancement in surface roughness. Moreover, the Hall effect measurements were also carried out to examine the electrical characteristics of NiO films. From this measurement, it was observed that the conductivity of NiO varies along with the Ag9+ ions fluence, and it appears that the variation in resistivity follows the change in band gap.