Demonstration of T2SLs InAs/InAsSb Based Interband Cascade Detector Supported by Immersion Lens for LWIR

Abstract

This paper presents the performance of an interband cascade long-wavelength infrared detector designed for high operating temperatures supported by immersion lenses. The device is based on the “Ga-free” InAs/InAsSb type-II superlattice with highly doped p+/n+ superlattice tunneling junctions connecting adjacent stages. Detectivity of the multi-junction heterostructure detector exceeding 1010 cm Hz1/2/W was estimated at wavelength λ ~ 9 µm and T = 210 K and ~ 3 × 108 cm Hz1/2/W for T = 300 K, achieving a tenfold improvement in detectivity in comparison to a device without an immersion lens and 30-fold improvement in detectivity in comparison to the single-stage device.