MW/LW photoresponse in dual-band n-B-n InAs/GaSb superlattice

The subband transitions in a dual-band n-B-n InAs/GaSb type-II superlattice detector are identified from the photoresponse (PR) spectra through a comparison with photoluminescence (PL) profiles. In the mid- and the long-wavelength (MW/LW) PR spectra achieved by changing the bias polarity, each spectrum individually shows a series of distinctive peaks related to the transitions from the hole subbands to the conduction one. Using a functional fit to the temperature-dependent MW-PR data, the Varshni's parameters are found to be (alpha, beta) = (2.50times10^-4 eV/K, 78 K).