Influence of substrate temperature and vacuum annealing on the structural properties of CdTe(111)/Si(100) thin films

Influence of substrate temperature and vacuum annealing on the structural properties of CdTe(111)/Si(100) thin film grown by hot wall epitaxy are investigated by SEM and XRD in this paper. SEM revealed that the average grain size increased with the increase of substrate temperature in the range of 200 degrees C to 310 degrees C, and the (111) pyramids become more apparent and more regular after annealing. XRD patterns showed that the main features of all samples were almost same, and had a perfect cubic phase preferential (111) orientation, only the peak intensities increased with the increase of substrate temperature. Stronger (111) diffraction peak intensity after annealing were observed and clear 2 Theta peak shift,to higher position as well as a lower FWHM value could be detected, indicating that lattice constants matched better with the standard value and the dislocation density decreased as compared with the as-grown samples. All results showed that a better crystalline quality was achieved by vacuum annealing.