X-Ray Characterization of Quaternary Antimonide Materials for Mid-IR lasers

摘要

The new mid-IR PL/optical pumping setup has been invaluable in the study of GaInAsSb and AlInAsSb materials that are MBE grown on a GaSb substrate. A PL intensity plot vs. wavelength for GaInAsSb grown at the University of New Mexico is displayed on the last page of the report. This PL trace was generated using the equipment purchased with the grant money. We believe that new alloys constructed from AlInAsSb and GaInAsSb will be the backbone of future antimonide-based semiconductor lasers. UNM grows the AlInAsSb using the digital alloy method. This technique employs the growth of several phase-stable alloys (binaries, ternaries, quarternaries, etc.), each a fraction of a monolayer to several monolayers thick. The net composition of these thin layers yields the desired alloy. For our work, InAs, AlSb, and InSb binaries were used to build the AlInAsSb quaternary. Whereas the research community has found that bulk growth of optical quality AlInAsSb with large Al is impossible due to a miscibility gap, UNM has recently shown that high-quality digital alloy growth of non-phase-separated AlInAsSb is possible up to 40% Al composition. One of the next steps is to determine the energy bandgaps of these materials, which as of now are unknown.