Appl. Phys. Lett. 105, 023512 (2014)

Detectors for mid-wavelength infrared (MWIR) radiation are typically based on semiconductor devices that require cryogenic cooling to achieve desirable operational parameters. Now, Alexander Soibel and co-workers from the California Institute of Technology in the USA have investigated the high-temperature performance of MWIR detectors composed of an n-doped InAsSb top contact, an AlAsSb barrier, and a lightly n-doped InAsSb absorber region. The team found that the quantum efficiency of the detectors is 35% without anti-reflection coating and does not change with temperature in the 77–325 K range, indicating the potential for room temperature operation. The detectors have a cut-off wavelength near 4.5 μm and exhibit a detectivity of 1 × 109 cm Hz1/2 W−1 at 300 K, and 5 × 109 cm Hz1/2 W−1 at 250 K, which is easily achievable with single-stage thermoelectric coolers. The scientists further investigated the bias voltage and dark current density as a function of temperature to understand the electronic characteristics of the devices.