No abstract

A novel design of quantum ring intersubband photodetectors is proposed based on quantum rings-in-well structure and its performance characteristics studied by simulation. The photon absorption occurs for intersubband transitions between quantum ring sub-bands and well states. The detector is expected to be better controlled over operating wavelength and normal incidence sensitivity in far infrared. Since the quantum well states change by electric field, the peak responsivity wavelength is voltage tunable. Our results show that increasing the bias voltage to 5 V leads to a red-shift about 4 lm in peak wavelength. For proposed detector a quantum-mechanical approach is introduced for calculation of photoconductive gain. Peak responsivity about 0.6 A/W at k = 20 lm is achieved at T = 77 K using this detector.