On the Hydrogen Sensing Behaviors of an InAlAs-Based Schottky Diode with a Thin Pt Catalytic Metal

Abstract

Electron capture in proton-lithium collisions at centre of mass energies below 10 keV is examined in the PSS approximation using a model potential for the e+Li' interaction. It is assumed that the level H(n = 2) is preferentially excited.Eigenvalues of the molecular Hamiltonian are found variationally, and radial and rotational coupling elements are calculated directly from these in prolate spheroidal coordinates. The coupling elements show strong dependence on the choice of coordinate system and have non-zero asymptotic limits. We use an adiabatic switching factor in the asymptotic region to ensure convergence of the cross sections. These are evaluated in the impact parameter approximation. Calculations involving both six and seven molecular states are performed. Radial coupling dominates the process at higher energies while rotational coupling is more important below 500 eV.Reasonable overall agreement with experiment is obtained in the energy range 500 eV to 8 keV, although our results still show considerable sensitivity to the choice of origin of the electron coordinates.

GaN Sensors with Metal–Oxide Mixture for Sensing Hydrogen-Containing Gases of Ultralow Concentration

“…This implies that the built-in electric field of the MS diode at equilibrium is sufficiently large for polarizing hydrogen atoms and explaining why a stable Á B was obtained for the reported MS sensors in a wide range of reverse-biased voltages. 1,6) At V 12 ¼ 2:5 V, Á B starts to increase with a voltage coefficient of 55 mV/V. Since the internal electric field has no contribution to the formation of dipoles, a further reduction in barrier height is believed to be due to hydrogen atoms trapped inside the mixture.…”

“…Experimental results for the measured t a are in agreement with those previously reported. [1][2][3]5) The shorter t a in a higher hydrogen concentration is due to a more efficient dissociation of hydrogen molecules. Compared with some other reported results, the response time of the proposed sensor at room temperature seems to be somewhat longer.…”

“…It is also strongly desirable to develop a sensitive and reliable hydrogen sensor that can in situ monitor the leakage of hydrogen-containing gases with low power consumption in real time. Therefore, several different types of field-effect hydrogen sensors were extensively investigated in past few decades, namely, metal-semiconductor (MS) Schottky diodes, [1][2][3][4][5][6][7][8] metal-oxide-semiconductor (MOS) diodes, [9][10][11][12][13][14] and field-effect transistors. [15][16][17] Among them, As-based or N-based compound semiconductors and Pd or Pt catalytic metals were typically employed as sensing platforms and sensing metals, respectively.…”

Sub-wavelength palladium antenna arrays for hydrogen optical detection in the infrared region

“…The Pd sub-wavelength structures can be used as optical H 2 sensors. Compared to the conventional H 2 sensors, such as combustion type 17) and semiconductor type, 18,19) the optical H 2 sensor based on subwavelength Pd antenna arrays possesses advantages because the optical sensor operates at room temperature and is H 2 selective. Operation at room temperature using light as the medium for signal transmission ensures the safety of the sensor operation.…”

Hydrogen Sensor with Pd Nanoparticles upon an Interfacial Layer with Oxygen

“…here has been considerable interest in the development of semiconductor-based hydrogen sensors for applications involving detection of leaks in a variety of space and ground based vehicles and processing systems. 1) Hydrogen is reported to be able to alter the effective charge at the metal-semiconductor interface or metal-insulator interface, resulting in changes in barrier height. Wide-gap semiconductors employing such an effect have been evidenced to be hydrogen sensors used at high temperatures and in harsh environments.…”