DUAL BAND INFRARED DETECTOR USING STEP MULTIQUANTUM WELLS WITH SUPERLATTICE BARRIERS

摘要

DUAL. BAND INFRARED DETECTOR USING STEPMULTIQUANTUM WELLS WITH SUPERLATTICE: BARRIERSAn infrared detector uses step quantum wells with superlattice barriers for dual-band detection. The step quantum wells are designed to have two bound states and acontinuum above the superlattice barriers. The bound-to-bound and bound-to-continuumtransitions are employed for the dual-band detection. The superlattice barriers are usedto extract the photocurrent from the bound-to-bound transition with a relatively lowexternal electric field while suppressing the thermionic emission, resulting in a smallerdark current. The photocurrent is tuneable by adjusting the energy level in the step wellrelative to the miniband by an eternal bias. Stark shifts of the energy levels in thequantum well allow for discrimination of the photocurrents due to BM and BCtransitions