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High operating temperature mid-wavelength infrared detectors based on InAs/InAsSb superlattices with electron block interfacial graded doping

Year: 2025

Type: article

Abstract: A high operating temperature mid-wavelength pBn infrared detector based on InAs/InAsSb superlattices with electron block interfacial graded doping is demonstrated. The photodetector exhibits saturated quantum efficiency from 77 K to 250 K under zero bias, requiring a −80 mV bias to fully extract photocurrent at 290 K. Under zero bias, the device achieves a peak responsivity of 1.69A/W at 150 K, corresponding to a quantum efficiency of 59.4%, and a detectivity of 1.24 × 1012 cm·Hz1/2/W at a cutoff wavelength of 5.0 µm. The dark current density of the pBn detector decreases from generation-recombination current limited 5.94 × 10−5A/cm2 to surface leakage current limited 2.95 × 10−5A/cm2 via the interfacial graded doping layer, resulting in a fitted generation recombination dark current of 1.37 × 10−6A/cm2. At 290 K, the cutoff wavelength extends to 6.2 µm, with a dark current density of 9.35 × 10−2A/cm2 and a peak quantum efficiency of 61.8% at 3.5 µm, leading to a specific detectivity of 9.87 × 109 cm·Hz1/2/W. The dark current of the interfacial graded doping device is lower than the prediction of Rule 07 at a temperature higher than 190 K, demonstrating the great potential of the InAs/InAsSb pBn photodetector for room temperature operation.

Source: Optics Express

DOI: 10.1364/oe.572457