A novel optical effect in InGaP compound collector heterojunction bipolar transistors

In this paper, we report the observation of a novel optical interaction that occurs in compound collector heterojunction bipolar transistors (CCHBT). This interaction causes an increase in the collector current, due to optical biasing, that can also be used to monitor the thickness of the InGaP layer in the CCHBT collector. We demonstrate this effect by examining I-V curves and C-V curves with and without illumination.