NONTHERMAL MICROWAVE MODULATION OF PHOTOLUMINESCENCE IN III-V-SEMICONDUCTORS

The effects of microwave electric fields on the photoluminescence (PL) from binary III-V semiconductors are compared to those of fields appl ied directly via Ohmic contacts. Significant differences are seen betw een the electric-field dependences of luminescence intensity changes f or microwave and directly applied fields, particularly in cases where the directly applied fields lead unequivocally to impact ionization. H ence, in contrast to previously published reports, it appears that mec hanisms other than impact ionization are significant in the microwave- PL coupling. We have also performed Monte Carlo simulations. These cal culations indicate that the energy dependence of the cross sections fo r capture of photoexcited carriers into competing radiative and nonrad iative processes plays an important role.