MICROSTRUCTURE OF SPARK-PROCESSED BLUE LUMINESCENT CDTE, GASB, AND INSB

Low frequency spark-discharges were applied to single crystalline wafe rs of CdTe, GaSb, and InSb. The samples were characterized by photolum inescence spectroscopy at room temperature using an excitation wavelen gth of 325 nm. The morphology was determined by optical, scanning elec tron and atomic force microscopy. In spite of the morphological differ ences occurring at micrometric scales, the spectral regions in which l uminescence is observed are almost the same. The origin of the blue lu minescence could be an opening of the bandgap due to a quantum confine ment effect. In order to estimate the size of the confinement regions, the effective mass approximation model was used. The obtained values of the size of these confinement regions (d) were: for CdTe, d = 30 An gstrom, for GaSb, d = 50 Angstrom and for InSb, d = 25 Angstrom.