Correlation between crystal structure and optical properties of copper- doped ZnO thin films

ZnO and Cu doped[1] (CZO) thin films were prepared by radio frequency sputtering. The structural and optical properties of thin films were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), optical spectrophotometer, and photoluminescence (PL) techniques. ZnO thin films showed crystalline and micro-stress defects in the crystal lattice. Annealing of CZO thin films increased the crystal size in the crystalline direction (002). The c lattice parameter decreased due to the matching of copper atoms in equilibrium positions. Also, the peak intensity of PL CZO thin films increased by annealing and Cu doping of ZnO thin films caused the emission of green light at 530 nm