Three-terminal-controlled field-effect resistive hydrogen sensor
2007; Elsevier BV; Volume: 124; Issue: 2 Linguagem: Inglês
10.1016/j.snb.2007.01.019
ISSN1873-3077
AutoresChing-Wen Hung, Kun‐Wei Lin, Hung-Chi Chang, Yan-Ying Tsai, Po-Hsien Lai, Ssu-I Fu, Tzu-Pin Chen, Huey-Ing Chen, Wen-Chau Liu,
Tópico(s)Advanced Memory and Neural Computing
ResumoBased on a Pd/oxide/AlGaAs pseudomorphic high-electron-mobility transistor (PHEMT) structure, an interesting three-terminal-controlled field-effect resistive hydrogen sensor is fabricated and studied. The influences of gate-source bias (VGS) on the hydrogen sensing properties are presented in this work. Experimental results show that the VGS bias significantly affects the resistance sensitivity, conductance variation, current variation, transient response, pressure-dependent and -independent rate constants, and response and recovery time constants. At 30 °C, a significant resistance response (SR=100×(Rair−RH2)/Rair) of 33.3% (82.8%) to 4.3 (9970) ppm H2/air is obtained at VGS = −0.6 V. Nevertheless, the largest conductance variation (ΔG) appears to be in the range between VGS = −0.3 and −0.4 V. An empirical equation is derived to explain the consistency between the calculated data and experimental results. Good linear relationship is observed between current variation and temperature under different VGS biases. The transient response at VGS = −0.3 V shows larger current variations, accompanying the longer response and recovery time constants than those at VGS = 0 V. Furthermore, on the basis of a kinetic adsorption analysis, the hydrogen pressure-dependent and –independent rate constants are obtained.
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