Type-II binary superlattices for infrared detector

III-V quantum wells and superlattices based on InAs/GaSb/AlSb, and related compounds have attracted many attentions due to their unique band alignments and physical properties. Recently, novel electronic and optoelectronic heterostructures have been proposed from this material system for hundred gigahertz logic circuits, terahertz transistors, RTDs, infrared laters, and infrared detectors. In this paper we will describe the ongoing research at the Center for Quantum Devices to develop the theory, modeling , growth, characterisation, and device fabrication techniques for this material system. We have demonstrated the first uncooled infrared detectors from type-II superlattices. The measured detectivity is more that 1 × 10⁸ cmHz^1/2/W at 10.6 μm at room temperature which is higher than the commercially available uncooled photon detectors at similar wavelength. In parallel, we have demonstrated the first high-performance p-i-n type-II photodiode in the very long wavelength infrared (VLWIR) range operating at T = 80K. The devices with cutoff wavelength of 16 mm showed a responsivity of 3.5 A/W at 80 K leading to a detectivity of ∼ 1.51 × 10¹⁰ cmHz^1/2/W. Similar devices with cutoff wavelengths up to 25 μm was demonstrated at 80 K. To enhance this technology further, we plan to move from quantum wells to quantum wire and quantum dots.