Voltage Pulse Modulation of Photoluminescence inp-GaP

A substantial enhancement of the photoluminescence of $p$-GaP and a shift to shorter wavelengths have been observed at 27 and 4°K, after the application of a voltage pulse of sufficient magnitude to raise the current appreciably above the value extrapolated from low fields. The current rises abruptly above a critical voltage. The observations are explained in terms of a model based on impact ionization of holes bound to isolated acceptors.