The Response Time of the High Operating Temperature and Very Long Wavelength Type-II Superlattice InAs/InAsSb Interband Cascade Photodetectors

The paper shows III-V InAs/InAsSb type-II superlattice (T2SL) very long wavelength (VLWIR, 100% cut-off wavelength,λ cut-off~~ ~16.5~μm at 330 K) interband cascade photodetector designed to operate >300 K. The device circumvents the low quantum efficiency (QE) and resistance issues of the conventional “thick absorber” photovoltaic detectors designed for high operating temperature (HOT, >300 K) conditions. The 3-stage detector was grown by molecular beam epitaxy (MBE) on the lattice-mismatched GaAs substrates and GaSb buffer layer where stages were connected by the highly doped typical n+/p+ tunnel junctions. The time constant of the unbiased device reaches ~2.83 ns (210 K) and ~0.5 ns (330 K).