MOCVD growth of Type-II superlattices for mid-wave and long-wave infrared detectors

Mid-wave and long-wave Infrared devices play an important role in cutting edge applications including gas detection, biomedical sensing, thermal imaging and light detection and ranging. Antimony (Sb) based type-II superlattice (T2SL) materials are a strong candidate for next generation infrared technologies due to advantageous manufacturability and flexible band engineering, when compared to the classically used mercury cadmium telluride (MCT). In the past, progress in MOCVD growth of Sb-containing T2SLs has been prohibited by the volatility of antimonides and the difficulties in forming interfacial layers. In this project, we propose to tackle these materials challenges and develop suitable device structures for MWIR and LWIR detectors. We will look into Ga-free strain balanced InAs/InAsSb T2SLs which offers superior minority life time, simpler interface switching process and tolerance to crystalline defects for integration on Si. In parallel, we will investigate Ga-containing InAs/GaSb T2SLs on InAs substrates using a GaAs-like interface for strain compensation and lattice engineering. Devices including diffusion doped planar pn diodes and mesa-etched diodes with advanced barrier architectures will be studied and compared.