CATHODOLUMINESCENCE IMAGE OF DEFECTS AND LUMINESCENCE-CENTERS IN ZNS GAAS(100)/

The spatial distributions of the cathodoluminescence (CL) emissions fr om thin ZnS films on GaAs(100) have been examined by the low-temperatu re CL measurement system combined with a transmission electron microsc ope (TEM). The correlation between these CL emissions and structural d efects were studied by comparing the monochromatic CL images with the TEM images for both plan-view and cross-sectional observations. It is found that the neutral acceptor-bound exciton associated emission (A(0 ),X) and the free-electron-to-ionized acceptor transition emission (e, A) are affected by the stacking fault distribution, The localization o f the emission due to the deep-level emission transition near the inte rface suggest the diffusion of Ga atoms from the GaAs substrate. The c haracteristic distributions of the CL emission regions can be explaine d by considering the competitions among the recombination channels of those radiative processes for each type of an excess carrier, an elect ron, or a hole. (C) 1996 American Institute of Physics.