Influence of catalytic reactivity on the response of metal-oxide-silicon carbide sensor to exhaust gases

Growth and Characterization of GaN Nanowires for Hydrogen Sensors

“…Since hydrogen is a hazardous, odorless, and highly flammable gas, hydrogen gas sensors play a critical role, particularly for fuel leak detection in spacecraft, automobiles, and aircraft, fire detectors, and diagnosis of exhaust and emissions from industrial processes. [5][6][7][8][9] Nanowires are becoming promising candidates for H 2 gas sensors due to their high surface-to-volume ratio. 3,[10][11][12] Wide-bandgap semiconductors such as GaN and ZnO have excellent potential for H 2 gas sensing because of their sensitivity to surface charge and ability to operate over large temperature ranges.…”

Comparison of MOS and Schottky W/Pt–GaN diodes for hydrogen detection

“…There is currently great interest in development of robust, wide bandgap semiconductor based combustion gas sensors for applications involving detection of leaks in a variety of space and ground based vehicles and hydrogen production processes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Wide bandgap semiconductors are capable of operating at much higher temperatures than Si because (bandgaps of 3.4 eV for GaN and 3.26 eV for the 4H-SiC polytype versus 1.1 eV for Si) [15].…”

“…Simple Schottky diode or field-effect transistor structures fabricated in GaN and SiC are sensitive to a number of gases, including hydrogen and hydrocarbons [1,7,[9][10][11]17,19]. The sensing mechanism is thought to be creation of a polarized layer on the semiconductor surface by hydrogen atoms diffusing through the metal contact [14]. One additional attractive attribute of both GaN and SiC is the fact that gas sensors based on this material could be integrated with high-temperature electronic devices on the same chip.…”

“…In addition, it may alter the effective charge at the interface between metal contacts and the semiconductor surface, leading to changes in barrier height. This is the effect used in semiconductor-based Schottky diode combustion gas sensors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. For GaN Schottky diodes, there is evidence that the presence of an interfacial oxide increases the magnitude of the change in barrier height [21] and hence the current flowing at a given bias on the device.…”

Remote sensing system for hydrogen using GaN Schottky diodes

“…In addition, these detectors would have dual-use in automobiles and aircraft, fire detectors, exhaust diagnosis and emissions from industrial processes [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The high-temperature capabilities of GaN electronics and sensors will reduce spacecraft launch weighs and increase satellite functional capabilities.…”