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).