Abstract

Optical measurements of semiconductor devices can provide direct information about carrier sweepout under high field conditions. In previous work, we exploited the nonlinearity in the luminescence in GaAs(1) to do picosecond time-resolved experiments on a GaAs photoconductor(2). The device consisted of an n-type active layer between ohmic contacts. The speed of the device, and the characteristic time of the luminescence decay is determined by the hole transit time in the device. From the luminescence decay we were able to extract a hole velocity of 2×10⁶cm/s at a field of 20kV/cm. We have used the same technique to measure carrier sweepout in a GaAs Schottky diode incorporated into a large capacitor at room temperature. Ohmic and blocking(ie Schottky) contacts can be helpful in discriminating between electron and hole transport processes. At a bias voltage of -4V, we have observed pulsewidth limited luminescence decays.

© 1984 Optical Society of America