Highly sensitive NpnP optoelectronic switch by AlAs regrowth

Abstract
A double‐heterostructure NpnP optoelectronic switching device, with an extreme optical sensitivity and low holding power, has been fabricated. A decrease in breakover voltage of 650 mV is obtained at a light illumination of only 5 nW for a 50×50 μm2 device. To achieve this high sensitivity, the surface generation/recombination currents at the edges of the devices have been reduced by passivating the device perimeter with a regrowth of 50 nm AlAs (lowly p doped).