INASSB INTISB SUPERLATTICE - A PROPOSED HETEROSTRUCTURE FOR LONG-WAVELENGTH INFRARED DETECTORS/

A novel superlattice (SL) heterostructure, comprising of InTlSb well a nd InAsSb barrier lattice matched to InSb, is proposed for long wavele ngth 8-12 mu m detectors. Improvements in the InTlSb epilayers' struct ural quality are expected, as it will be sandwiched between higher qua lity zinc-blende InAsSb epilayers. Preliminary energy band calculation s of 30 Angstrom InAs0.07Sb0.93/100 Angstrom In0.93Tl0.07Sb SL show th e band alignment favorable to type I with three heavy-hole subband con finement in the valence band and a partial electron subband confinemen t in the conduction band due to the small conduction band offset. Incl uding the effect of strain indicates significant changes in the band o ffsets, with optical bandgap essentially unaltered. The optical band g ap of this SL was computed to be 0.127 eV (9.7 mu m) at 0K, indicating its potential for long wavelength applications.