Epitaxial growth and characterization of Cd1−xMnxTe films on Si(1 1 1) substrates

Semiconductors structures with high quality and low cost have been developed and applied in industry on a large scale. The knowledge of basic properties of semiconductor materials growth is important for many technological applications. Cd 1-x Mn x Te films have been used successfully in optoelectronic, solar cells and high energy detectors applications. However, despite the high potential for application of these films, fundamental growth studies on Si(1 1 1) substrate are not extensively explored. In this study, two Cd 1−x Mn x Te (CMT) films (with different Mn concentrations) were successfully prepared on Si(1 1 1) substrate employing molecular beam epitaxy. The morphology and surface roughness of the films were investigated using atomic force microscopy (AFM). X-ray diffraction was used to investigate the structural quality and to determine the Mn concentration of the samples. It shows that the films have only (1 1 1) orientation despite a lattice mismatch of almost 19%. Room temperature micro-photoluminescence (µ-PL) spectra shows a high intensity band edge emission and very low intensity defect related emission. Raman spectroscopy of the samples was carried out in order to obtain the vibrational modes. First, second and third order CdTe-like and MnTe-like longitudinal-optical (LO) phonon modes were observed. These results demonstrate the potential of these structures for room temperature applications.