Comparative microstructural studies using different methods: Effect of Cd-addition on crystallography, microstructural properties, and crystal imperfections of annealed nano-structural thin CdxZn1-xSe films

Thermally evaporated zinc-cadmium selenide (CdxZn1-xSe) thin films with different Cd-concentration (0.0 <= x <= 1.0, at%) have been prepared. The deposition process of films was controlled where the vacuum was fixed at approximate to 10(-5) Pa, the film thickness at 7500 angstrom, and the rate of deposition at approximate to 100 angstrom/s. These prepared films have been annealed under vacuum at 500 degrees C for 2-hrs. X-ray diffraction, XRD study confirmed the crystallinity nature of annealed CdxZn1-xSe films with a face-centered cubic structure, which is transformed into a hexagonal structure with increasing the cadmium. Energy-dispersive X-ray analysis shows that there is good consistency between the detected and selected element ratios. Scherrer, Williamson-Hall, Size-Strain plot, and Halder-Wagner methods were used to examine the crystallite size and microstrain using XRD peak-broadening analysis. According to the Williamson-Hall method the crystallite size increased from 14.70 nm to 31.30 nm and microstrain decreased from 14.19 x 10(-3) to 7.29 x 10(-3). The Cd-addition leads to improving the film crystallinity and reducing the crystal imperfections.

Automated summary

Thermally evaporated zinc-cadmium selenide thin films with different cadmium concentration were prepared and annealed under vacuum to improve crystallinity and reduce crystal imperfections. The study confirmed changes in crystal structure and grain size with increasing cadmium content, showing the beneficial effects of cadmium addition on film quality.