Optoelectronic switch performance in double heterostructure-emitter bipolar transistor

The behavior of optoelectronic switch is examined in GaAs-AlGaAs double heterostructure-emitter bipolar transistors with exposed p(+)-GaAs surface, n-GaAs surface, and N-AlGaAs passivated surface. Due to the symmetric structure with respect to the base layer, the devices operate as bi-directional switches which result from the avalanche multiplication and transistor action in the transport mechanism. The devices also show optical functions related to the potential barrier height and breakdown voltage controllable by incident light. Moreover, the device with AlGaAs passivated surface exhibits a highest optical sensitivity and a lowest holding power among the studied devices because of the effective decrease of the surface recombination current. (C) 2001 Elsevier Science Ltd. All rights reserved.