MICROWAVE MODULATED PHOTOLUMINESCENCE IN DOPED GAAS

Microwave modulated photoluminescence (MMPL) is a spectroscopy wherein a sample is placed in the electric field maximum of a microwave cavit y and is simultaneously subjected to continuous optical pumping and ch opped microwave electric fields, In this work, MMPL has been pet-forme d on GaAs epilayers with n- and p-type doping ranging Si om 10(15) to 10(20) cm(-3), The MMPL spectra can be experimentally separated into t wo categories, fast and slow. The interaction is predominately faster in the lightly doped samples and slower in the heavily doped samples, These observations are consistent with a more-or-less constant rate of lattice heating per free carrier through free carrier energy relaxati on. The magnitude of the temperature modulation through free carrier t hermalization with the lattice, and hence the amplitude of the slower component of the MMPL, can be explained in terms of theoretical estima tes for the rate of energy loss of the accelerated free carriers.