An optically triggered double heterostructure linear bilateral phototransistor

Abstract

We describe a double heterostructure phototransistor. Such a device potentially offers the important properties of high blocking voltage for both polarities of applied bias, high gain for both polarities of applied bias, and linear current-voltage characteristic through the zero bias point. Thus this device has many of the valuable properties of a normally OFF metallic switch. Experiments with n-Ga1-xAlxAs, p-Ga, n-Ga1-xAlxAs structures demonstrated bilateral gain of 180 and a blocking voltage of ±10 volts in one wafer with a 2.1 µm thick GaAs base, and bilateral gain greater than 3000 with blocking voltage of ±2.6 volts in a wafer with 0.3 µm thick GaAs base.