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, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{\textit {cut}-\textit {off}}~\sim ~16.5~\mu $ </tex-math></inline-formula>m 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).