(A1,Ga)Sb Alloys and GaSb/A1Sb Multiple Quantum Wells for Infrared Optoelectronic Device Applications

In this program various devices based on the AlGaSb material system for optical source and detector applications will be studied. Various (Al,Ga)Sb based on photodetectors structures including MSM (metal-semiconductor-metal), PIN, SAGM (Separate absorption graded and multiplication), etc., will be fabricated and characterized. In this area preliminary results have been very encouraging. Record breakdown voltages (6V) for molecular beam epitaxial (MBE) grown PIN diodes without surface passivation have already been obtained, and it is expected that significant progress will be made by pursuing a more comprehensive program. In addition to detectors, GaSb/AlSb quantum well optical modulators and quantum well lasers will be studied along with the integration of PIN and MSM detectors with the n- and p-channel FETs based on AlSb/InAs/GaSb. The optimal MBE conditions for the material growth will be established through reflection high energy electron diffraction (RHEED) and Auger electron spectroscopy. The structural properties of the materials will be characterized by x-ray diffraction. The electrical and optical properties will be characterized Hall measurements and photoluminescence. Finally, GaSb MSM, PIN, avalanche and SAGM photodetectors will be fabricated and characterized.