Using Optical Activation to Create Hydrogen and Hydrogen-Containing Gas Sensors

2020 ◽  
Vol 854 ◽  
pp. 87-93 ◽  
Author(s):  
Khafiz M. Salikhov ◽  
Nikolay D. Stoyanov ◽  
Tatyana V. Stoyanova

It was found that at room temperature the value of the photoinduced current of Schottky diodes based on heterostructures InP/GaInAs/Pd at a hydrogen concentration of 0.03% is reduced by two orders of magnitude compared to the value without hydrogen. The value of the photoinduced current depends on the thickness of the depleted region on the surface of the semiconductor. A small change in the charged layer of H+ can cause a significant change in the thickness of this region and as a result, a strong change in the photoinduced current. This effect on current is much stronger than the influence of hydrogen concentration or capacitance without optical activation. As a result, it becomes possible to create hydrogen and hydrogen-containing gas sensors with much better sensitivity at room temperature. The original design of a miniature H2 sensor including an IR LED, a Schottky diode with a Pd contact, a Peltier cooler and a thermosensor is demonstrated.

Author(s):  
Е.А. Гребенщикова ◽  
В.Г. Сидоров ◽  
В.А. Шутаев ◽  
Ю.П. Яковлев

AbstractThe variation rate of the short-circuit photocurrent of Pd/ n -InP Schottky diodes is studied as a function of the presence of hydrogen in a gas mixture with H_2 concentrations of 1–100 vol %. It is shown that upon the simultaneous exposure of the Schottky diode to a hydrogen-containing gas mixture and to light (λ = 0.9 μm), the hydrogen concentration in the gas mixture and the Pd/ n -InP diode photocurrent variation rate are related exponentially. The Schottky-diode response rate to the presence of hydrogen in the gas mixture increases with the illumination intensity.


2000 ◽  
Vol 640 ◽  
Author(s):  
Q. Zhang ◽  
V. Madangarli ◽  
Y. Gao ◽  
T. S. Sudarshan

ABSTRACTForward and reverse current – voltage (I–V) characteristics of N and P-type Schottky diodes on 6H-SiC are compared in a temperature range of room temperature to 550K. While the room temperature I–V characteristics of the N-type Schottky diode after turn-on is more or less linear up to ∼ 100 A/cm2, the I–V characteristics of the P-type Schottky diode shows a non-linear behavior even after turn-on, indicating a variation in the on-state resistance with increase in forward current. For the first time it is shown that at high current densities (> 210 A/cm2) the forward voltage drop across P type Schottky diodes is lower than that across N type Schottky diodes on 6H-SiC. High temperature measurements indicate that while the on-state resistance of N type Schottky diodes increases with increase in temperature, the on-state resistance of P type Schottky diodes decreases with increase in temperature until a certain temperature. While the N-type diodes seem to have soft breakdown characteristics, the P-type diodes exhibit more or less abrupt breakdown characteristics.


Author(s):  
Bhanu P. Sood ◽  
Michael Pecht ◽  
John Miker ◽  
Tom Wanek

Abstract Schottky diodes are semiconductor switching devices with low forward voltage drops and very fast switching speeds. This paper provides an overview of the common failure modes in Schottky diodes and corresponding failure mechanisms associated with each failure mode. Results of material level evaluation on diodes and packages as well as manufacturing and assembly processes are analyzed to identify a set of possible failure sites with associated failure modes, mechanisms, and causes. A case study is then presented to illustrate the application of a systematic FMMEA methodology to the analysis of a specific failure in a Schottky diode package.


Nanoscale ◽  
2021 ◽  
Author(s):  
Soon-Hwan Kwon ◽  
Tae-Hyeon Kim ◽  
Sang-Min Kim ◽  
Semi Oh ◽  
Kyoung-Kook Kim

Nanostructured semiconducting metal oxides such as SnO2, ZnO, TiO2, and CuO have been widely used to fabricate high performance gas sensors. To improve the sensitivity and stability of gas sensors,...


Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2123 ◽  
Author(s):  
Wenli Li ◽  
Yong Zhang ◽  
Xia Long ◽  
Juexian Cao ◽  
Xin Xin ◽  
...  

The unique properties of MoS2 nanosheets make them a promising candidate for high-performance room temperature gas detection. Herein, few-layer MoS2 nanosheets (FLMN) prepared via mechanical exfoliation are coated on a substrate with interdigital electrodes for room-temperature NO2 detection. Interestingly, compared with other NO2 gas sensors based on MoS2, FLMN gas sensors exhibit high responsivity for room-temperature NO2 detection, and NO2 is easily desorbed from the sensor surface with an ultrafast recovery behavior, with recovery times around 2 s. The high responsivity is related to the fact that the adsorbed NO2 can affect the electron states within the entire material, which is attributed to the very small thickness of the MoS2 nanosheets. First-principles calculations were carried out based on the density functional theory (DFT) to verify that the ultrafast recovery behavior arises from the weak van der Waals binding between NO2 and the MoS2 surface. Our work suggests that FLMN prepared via mechanical exfoliation have a great potential for fabricating high-performance NO2 gas sensors.


2006 ◽  
Vol 113 (2) ◽  
pp. 797-804 ◽  
Author(s):  
M. Ali ◽  
V. Cimalla ◽  
V. Lebedev ◽  
H. Romanus ◽  
V. Tilak ◽  
...  

2007 ◽  
Vol 131-133 ◽  
pp. 425-430 ◽  
Author(s):  
Anis M. Saad ◽  
Oleg Velichko ◽  
Yu P. Shaman ◽  
Adam Barcz ◽  
Andrzej Misiuk ◽  
...  

The silicon substrates were hydrogenated at approximately room temperature and hydrogen concentration profiles vs. depth have been measured by SIMS. Czochralski grown (CZ) wafers, both n- and p-type conductivity, were used in the experiments under consideration. For analysis of hydrogen transport processes and quasichemical reactions the model of hydrogen atoms diffusion and quasichemical reactions is proposed and the set of equations is obtained. The developed model takes into account the formation of bound hydrogen in the near surface region, hydrogen transport as a result of diffusion of hydrogen molecules 2 H , diffusion of metastable complexes * 2 H and diffusion of nonequilibrium hydrogen atoms. Interaction of 2 H with oxygen atoms and formation of immobile complexes “oxygen atom - hydrogen molecule” (O - H2 ) is also taken into account to explain the hydrogen concentration profiles in the substrates of n-type conductivity. The computer simulation based on the proposed equations has shown a good agreement of the calculated hydrogen profiles with the experimental data and has allowed receiving a value of the hydrogen molecules diffusivity at room temperature.


2015 ◽  
Vol 28 (5) ◽  
pp. 795-831 ◽  
Author(s):  
Jun Zhang ◽  
Xianghong Liu ◽  
Giovanni Neri ◽  
Nicola Pinna

2013 ◽  
Vol 717 ◽  
pp. 113-116
Author(s):  
Sani Klinsanit ◽  
Itsara Srithanachai ◽  
Surada Ueamanapong ◽  
Sunya Khunkhao ◽  
Budsara Nararug ◽  
...  

The effect of soft X-ray irradiation to the Schottky diode properties was analyzed in this paper. The built-in voltage, leakage current, and work function of Schottky diode were investigated. The current-voltage characteristics of the Schottky diode are measured at room temperature. After irradiation at 70 keV for 55 seconds the forward current and leakage current are increase slightly. On the other hand, the built-in voltage is decrease from the initial value about 0.12 V. Consequently, this method can cause the Schottky diode has low power consumption. The results show that soft X-ray can improve the characteristics of Schottky diode.


Sign in / Sign up

Export Citation Format

Share Document