Saturation behavior of extrinsic photoconductivity in GaP light emitting diodes at high infrared intensities

Abstract

Saturation of extrinsic photoconductivity in GaP:N(Zn, Te) diodes could be achieved by excitation with a TEA-CO2-laser. At wavelengths in the 10 mgrm range intensities of several 100 kW/cm2 being near the damage threshold were applied. Carrier lifetimes of 60 ps at 4.2 K and 200 ps at 77 K could be estimated. The only conceivable mechanism explaining these short time constants is the capture of infrared excited holes by ionized shallow acceptors in the highly compensated p-side of the diode.