Wide bandgap semiconductor gas and liquid sensors have potential uses in detecting fuel leaks in spacecraft, automobiles and aircraft, fire detectors, exhaust diagnosis and emissions from industrial processes as well as in in-situ monitoring in chemical processes. Gallium nitride (GaN) and silicon carbide (SiC) are capable of operating in harsh environments and higher temperatures than more conventional semiconductors such as silicone (Si) because of their large bandgap. Simple Schottky diodes, metal oxide semiconductor (MOS) diodes, or field-effect transistor structures fabricated of GaN or SiC are sensitive to a number of gases, including hydrogen and some hydrocarbons. An additional attractive attribute of GaN and SiC materials is that gas sensors based on them can be integrated with high-temperature electronic devices on the same chip.
The PI has demonstrated the feasibility of combustion gas detectors with extremely fast response times and capable of operating at high temperatures, eliminating bulky and expensive cooling systems. The device structure is essentially identical to that employed for power rectifiers and emphasizes how similar structures can be used for both gas sensing and high power electronics applications. To expand the capabilities of such solid-state, dual-use systems, the PI is planning to develop several new classes of gas and liquid sensors for inexpensive, low-cost, low weight monitoring of gases and liquids released during fires. The devices take advantage of a strong materials and manufacturing base at Sterling Semiconductor and the sensor design and fabrication abilities of faculty and students at the University of Florida. The basic science behind the sensing mechanisms in GaN and SiC structures will be investigated, and design/optimization will be carried out based on the results from new, stable metalization schemes and novel approaches to sensing the relevant gases and liquids.
Broader Impact:
The University of Florida has a Student Science Training Program run every summer by its Center for Precollegiate Education and Training. The program brings in a select group of 10th and 11th grade students to do research in science and engineering. Two of these students will participate in this research. The Center also runs an NSF Teacher Research Update Experience (TRUE) program during the summer. The PI will present a lecture on solid-state sensors at the program and will collaborate with interested teachers to translate the research experience into modules, which can be taken back to middle and high schools. At the end of their stay, the modules will be tested on students participating in the program.
