PHOTOGENERATED CARRIER DYNAMICS UNDER THE INFLUENCE OF ELECTRIC-FIELDS IN III-V SEMICONDUCTORS

We present a rigorous analysis of the effects of electric fields on ti me-resolved photoluminescence SpeCtra in semiconductors. It is based o n the solution of the semiconductor transport equations using the drif t-diffusion approximation. The results show that the effect of the fie ld alone on the photoluminescence decay can be distinguished from that of charge separation and field-enhanced surface recombination. The an alysis is applied to two different sets of experiments. In the first, we use femtosecond luminescence upconversion to observe the ultrafast charge separation in the space-charge region, and screening of the ele ctric field under high-injection conditions. The second group of exper iments was conducted on heterostructures of GaAs/GaxIn1-xP under exter nally applied bias using time-correlated single-photon counting detect ion in the picosecond time domain. The use of the method for extractin g charge-transfer velocities across semiconductor interfaces is discus sed.