Structural and Optical Properties of Zn1-XCrXO Thin Films Deposited by Magnetron Sputtering
In this study, Zn1-xCrxO thin films were successfully fabricated on glass substrates by magnetron sputtering technique. The relationship between Cr doping concentration and the structural and optical characteristics of the produced samples was investigated by X-ray diffraction (XRD), optical transmittance and photoluminescence(PL). EDS results demonstrate that Cr ions are substitutionally incorporated into ZnO. XRD analysis reveals that all the prepared films with a preferential c-axis orientation exhibit the wurtzite structure of ZnO. The spectrometer transmittance data indicates that the band gap energies of the Zn1-xCrxO films are calculated by a linear fitting method. The band gap is found to be large with the increasing dopant concentration. The PL spectra suggest that all the samples have an ultraviolet emission peak centered at 370 nm. With the improved Cr-doped concentration, the peaks of ultraviolet emission have a blue shift to the region of higher photon energy, which is coincident with those values calculated by the linear fitting from the transmittance data. It is also found that the intensity of ultraviolet emission has been remarkably improved when Cr content is approximately 2.0at.%, but it is decreased when doping concentration of Cr is excessively high.
Chengming Li, Chengbao Jiang, Zhiyong Zhong and Yichun Zhou
C. F. Fu et al., "Structural and Optical Properties of Zn1-XCrXO Thin Films Deposited by Magnetron Sputtering", Materials Science Forum, Vol. 687, pp. 750-755, 2011