InTlAsBiSb Detector Technology Novel Thallium and Bismuth based
materials provide advantages As an alternative to HgCdTe, a
number of III-V semiconductor systems have been investigated due
to a potential for higher uniformity, yield, and mechanical
strength. Some of the material system researched for uncooled
mid and far-infrared detectors include: InSb, InAsSb, InTlSb,
InSbBi, and InTlAsSb. Also, much work recently has been devoted
towards type-II InAs/GaSb superlattices. As an alternative to
the InAsSb system, InTlSb is also a potential material for λ> 8
μm detectors. By incorporating Tl into an InSb lattice, the
material can go from a semi-conducting to a semimetallic phase
(Eg<0). Unfortunately, due to a large miscibility gap which
limits the Tl incorporation to about 15 %, it was almost
impossible to incorporate any Tl experimentally. The first
epitaxial growth of InTlSb on GaAs substrates using LP-MOCVD was
done at the Center for Quantum Devices. Figure b shows the
spectral response of In1- xTlxSb photo