DENSITY-OF-STATES IN THE GAP OF CDTE-V DEDUCED FROM THE MODULATED PHOTOCURRENT TECHNIQUE

The density of states in the gap of CdTe:V is studied by means of opti cal transmission, spectral photoresponse, dark conductivity, and modul ated photocurrent measurements. Four peaks of localized gap states are identified, the two main ones consisting of donor states located at 1 .1 eV below the conduction band and states located 0.75 eV above the v alence band, respectively. The dark conductivity is shown to be domina ted by holes, while the photoconductivity is shown to be dominated by electrons or holes, depending on temperature and light intensity.