An Electrically-Controllable Multi-spectral Quantum Dot Infrared Photodetector with high Photodetectivity

摘要

We present an electrically-controllable multi-spectral quantum dot infrared photodetector (QDIP). The QDIP consists of vertically-stacked InAs quantum dots layers with two different capping layers for MWIR and LWIR absorption, respectively. The multi-spectral QDOP is capable of simultaneously detecting multi-spectral normal incidence through inter-subband transitions in the three-dimensional (3-D) confined quantum dot nanostructures. The QDIP showed multi-color IR detection bands centered at 5.6um, 7.7 μm and 10.0μm, respectively. By tuning the bias voltage, the detection band can be individual turned on. High photodetectivity of ＞ 2.3 × 10~(10)cmHz~(1/2)/W were obtained for these IR detection bands. The voltage-controllable detection band selection enables real-time system reconfiguration to focus on the band of interest. The vertically-stacked device structure allows easy construction of focal plane arrays (FPA).