Cr-doped ZnO thin films are prepared on glass substrates by the magnetron sputtering technique. An X-ray diffraction (XRD) is used to analyze the structural properties of the thin films. It indicates that all the thin films have a preferential c-axis orientation. The peak position of the (002) plane shifts to the higher 2θ value, and the peak intensity decreases with the increase of Cr doping. The results of the scanning electron microscopy (SEM) show that the surface morphology becomes loose with the increase of Cr doping. Besides, it is found from the photoluminescence (PL) measurement at room temperature that the ultraviolet emission peak and green emission band are located at 375 nm and 520 nm, respectively, and both intensities of them decrease with the increase of the Cr doping concentration, while the band gap of the ultraviolet emission shifts to the lower wavelength. The experimental results confirm that the optimal Cr doping concentration is 2 at. %.
The free-standing diamond films are deposited on molybdenum substrate by direct current jet chemical vapor deposition (DCJCVD). X-ray diffraction,Raman spectroscopy and cathodoluminescence (CL) measurement are used to investigate the films structure and defects related to electron transition properties of the diamond films. The X-ray diffraction spectrum reveals that the diamond films have the polycrystalline cubic structure with diffraction peaks at 43.88o and 75.24o. A sharp peak at 1331.8 cm-1 and a broad band at about 1250-1550 cm-1 from Raman spectrum are attributed to diamond phase and sp2-type carbons,respectively. Two emission peaks at 440 nm and 530 nm,associated with dislocation defects and nitrogen and vacancy complexes respectively,are observed in cathodoluminescence spectrum. In addition,in order to understand both emission processes,a simple energy level scheme is suggested.
