Influences of sputtering power and annealing temperature on the structural and optical properties of Al2O3:CuO thin films fabricated by radio frequency magnetron sputtering technique

Abstract

In the present study, we report the high visible to near infrared (NIR) transparent Al2O3:CuO thin films prepared using homemade high purity sputtering target by radio frequency magnetron sputtering technique with sputtering powers of 100, 200 and 300 W at room temperature and the prepared films were annealed at 300, 600 and 1000 °C for 1 h. X-ray diffraction analysis confirmed the amorphous formation of the deposited films. The obtained X-ray profiles of the sputtering target are refined using Rietveld refinement technique through the program package of general structure analysis system with EXPGUI interface. Optical study showed the sputtering power and annealing temperature persuaded red shift in absorption edge and as a consequence the shrinkage in optical band gap was observed. The obtained high average transparency of 87–96% in the wavelength range 400–1100 nm validates the transmittance of as-deposited and annealed Al2O3:CuO thin films is well extended into the near infrared region. The obtained optical transmittance and absorbance data were utilized to calculate various optical parameters.