Solid-State and Opto-Electronics Laboratory
Solid-State and Opto-Electronics Laboratory specializes in growth, fabrication and advanced characterization of optoelectronic devices including semiconductor lasers. We specialize in narrow-band semiconductors, such as LED’s, lasers and receivers. The devices are most efficient in an important mid-IR, 3-4 micron spectral region, where hydrocarbons have strong absorption lines. The LED’s and receivers are thus ideally suited for hydrocarbon detection in air, for example for natural gas leak detection, identification of hazardous substances and many others. Our laser technology demonstrated exceptionally powerful mid-IR lasers for military and space applications.
The laboratory equipment park includes everything which is necessary to complete the production process of an optoelectronic device – from design to packaging. Powerful computer simulation packages such as BeamProp, COMSOL and PADRE are used for device structure design. The designed structures are grown by Molecular Beam Epitaxy (MBE) in VEECO Gen 930 reactor including materials of III and V groups. Immediately after growth epitaxial materials are characterized with high-resolution X-ray diffractometry and photoluminescence and carrier lifetime measurements with time resolution from 200 femtoseconds to microseconds providing rapid feedback for optimization of growth. Powerful optical Namarsky microscopes with magnification of 1500 times and Veeco Dimension atomic force microscope are used to monitor surface morphology of the grown wafers. The wafers are further processed in a Class 100 clean room. The typical procedures include oxygen plasma cleaning, e-beam metal and optical quality dielectric deposition, plasma etching, substrate lapping, polishing and cleaving. Unpackaged devices are tested with probe stations operating from liquid helium to room temperatures and above. The good devices are mounted with chip bonding machines and electrically connected to the mount’s terminals using ball and wedge wire bonding machines.
The SBU mid-IR laser technology has been successfully deployed at Mars Curiosity mission. The LED-receiver pairs are being currently used in development of compact, low power methane sensors. In this development a partner company utilizes the SBU LED technology to design and manufacture a low-cost sealed multi-gas sensor with a 10 year lifetime. The sensor is utilizing the mid-infrared range where multiple common gasses (CO2, water vapor, methane, formaldehyde etc.) have very strong absorption signatures.