Trap-Assisted Gas Sensing Mechanism in ${ m Pd/TiO}_{2}/{ m SiO}_{2}/{ m SiC}$ Capacitors at High Temperatures
Trap-Assisted Gas Sensing Mechanism in ${
m Pd/TiO}_{2}/{
m SiO}_{2}/{
m SiC}$ Capacitors at High Temperatures
复制标题
${ m Pd/TiO}_{2}/{ m SiO}_{2}/{ m SiC}$ 电容器在高温下的陷阱辅助气体传感机制
作者：
M. Weng;R. Mahapatra;A. Horsfall;N. Wright
我们证明了高温环境下的气体浓度可以通过由二氧化硅和二氧化钛组成的碳化硅上的介电堆的泄漏电流来测量。泄漏电流的变化可以用陷阱辅助传导模型来解释，其中观察到势垒高度取决于气体的浓度。显示了传感器在暴露于氢和氧下的行为，我们提出观察到的变化可以用氧化层下带弯曲的变化来解释。该检测技术的灵敏度不受电介质上电场的影响，优于50ppm。与传统的基于电容的测量相比，使用低电场提供了在高温下长期工作的可能性。
We demonstrate that the gas concentration in a high-temperature environment can be measured using the leakage current through a dielectric stack on silicon carbide, comprising silicon dioxide and titanium dioxide. The variation in the leakage current may be explained by the trap-assisted conduction model, where the barrier height is observed to be dependent on the concentration of gas. The behavior of the sensors under exposure to hydrogen and oxygen is shown and we propose that the observed change may be explained by the change in band bending under the oxide layer. The sensitivity of this detection technique is not influenced by the electric field across the dielectric and is better than 50 ppm. The use of a low electric field in comparison to conventional capacitance-based measurements offers the possibility of long-term operation at elevated temperatures.