Voltage-tunable dual-band InAs quantum-dot infrared photodetectors based on InAs quantum dots with different capping layers

Abstract

A voltage-tunable, dual-band, InAs quantum-dot infrared photodetector (QDIP) is reported. The QDIP consists of InAs quantum dot layers with GaAs and In0.20Ga0.80As capping layers for extended middle infrared (EMIR, 6–8 µm) and long-wave infrared (LWIR, 8–12 µm) detection, respectively. Voltage-tunable single- and dual-band operations were obtained with good photoresponsivity and photodetectivity selectivity. Since the detection band of the QD FPA can be individually tuned by engineering the capping layers of the InAs QDs, this design approach offers great flexibility in detection for a given spectral region.