Study of the nonlinear optical absorption and refraction of indium doped zinc oxide (IZO) thin films using Z-scan technique

Abstract

Indium doped zinc oxide (IZO) thin films were grown on sapphire substrate by radio frequency (RF/DC) magnetron sputtering technique. The structural characterization and surface morphology of IZO thin films were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The XRD results show that the samples exhibit polycrystalline characteristics and still retained wurtzite structure. The surface morphology of the samples reveals the average crystallite sizes are increased as indium content. In addition, the linear optical properties of IZO thin films were studied by UV-VIS spectrometer with wavelength range 200-900 nm. The high transmittances and the band gap values were observed in both thin films. Moreover, the nonlinear optical absorption and refraction of IZO thin films were investigated using nanosecond Z-scan technique. These samples show self-focusing optical nonlinearity and good two-photon nonlinear optical absorption behaviors. Therefore, these studies make the IZO thin films as the applications in nonlinear optical devices.