A Pd/oxide/InAlAs metal-oxide-semiconductor (MOS) type metamorphic high electron mobility transistor (MHEMT)-based hydrogen sensor is fabricated and investigated. In comparison with the conventional HEMT-based sensors, the MOS MHEMT-based sensor exhibits significantly high sensitivity to the hydrogen. The found hydrogen sensing response is as high as 300%. Using the thermodynamic analysis to estimate the enthalpy value of hydrogen adsorption, the value for the proposed sensor is much lower than that for the other reported HEMT-based sensors. The MHEMT-based sensors are demonstrated to have a relatively fast response as comparing to other HEMT-based ones. The response time of the device is approximately 10 s under exposure to a 1% H2/air gas. Consequently, the performance of the studied sensors shows the promise characteristics for practical applications. © 2010 Professor T. Nejat Veziroglu.
Tsai, T. H., Chen, H. I., Chen, T. Y., Chen, L. Y., Liu, Y. J., Huang, C. C., … Liu, W. C. (2010). Hydrogen sensing properties of a Pd/oxide/InAlAs metamorphic-based transistor. International Journal of Hydrogen Energy, 35(8), 3903–3907. https://doi.org/10.1016/j.ijhydene.2010.01.058