Spontaneous radiation effects of the current filament in GaAs photoconductive semiconductor switches

Abstract

The spontaneous radiation effects of current filament in high gain gallium arsenide(GaAs) photoconductive semiconductor switches(PCSS) have been studied by using the statistical-physical method. The spontaneous radiation law of the current filament in high gain GaAs PCSS was derived. In GaAs samples the concepts for the wavelength distribution function of the radiation intensity were introduced. The average radiative recombination coefficient of the current filament in high gain GaAs PCSS,(883 nm) ≈ 0.1125, was approximately determined. The relationship between radiative recombination coefficients of different radiation wavelengths and the average radiative recombination coefficient was deduced. It was verified that the optical output energy of the peak wavelength, =890 nm, coincided with the experimental observations. The density distribution of the carrier from the recombination radiation at the tip of the filament is revealed in theory. The results show the ratio of volume to area of the current filament and the average carrier density inside the current filament are two primary factors that affect the radiation effect of current filament. Reabsorption of 876 nm radiations plays a dominant role for the maximum density of carrier from the recombination radiation. The maximum density of carrier from the recombination radiation at the tip of the filament is approximately 1–2 orders of magnitude lower than the average carrier density inside the current filament.