LOCALIZED STATES OF A-GAP-N BY NITROGEN ION-BEAM-ASSISTED DEPOSITION

Nitrogen treated amorphous gallium phosphide (a-GaP:N) has p-type cond uction with nitrogen induced acceptor levels and wider mobility gap in the 3 eV range rather than crystal GaP (2.26 eV). The levels play a r ole for luminescent centers in the blue light region. According to ac- photoconductivity measurements, tail states at valence mobility band d ecreased with increasing nitrogen ion concentration. Because the tail states are due to Ga-Ga wrong bond, the reduction of the states may be described in terms of Ga-N-Ga and Ga-N related bonds.