MEASUREMENT OF MINORITY-CARRIER LIFETIME BY TIME-RESOLVED PHOTOLUMINESCENCE

Much of the current compound semiconductor device research is based on minority-carrier devices such as heterojunction bipolar transistors and diode lasers. The improvement of minority-carrier-parameters is the focal point of much ongoing materials research. The minority-carrier lifetimes of III-V compound semiconductors are most easily characterized by time-resolved photoluminescence. This is a quick and contactless technique which directly measures the excess minority-carrier carrier density. By using a focused laser beam as the excitation source, the required sample area may be very small. In special diagnostic structures which utilize a confinement or passivating layer, the interface recombination velocity can be determined. Here I will describe the measurement theory and measurement techniques which are used in our laboratory. Recent developments in the III-V materials technology will be reviewed.