A new Pd-oxide-Al0.3Ga0.7As MOS hydrogen sensor

A new and interesting Pd-oxide-Al0.3Ga0.7 As MOS hydrogen sensor has been fabricated and studied. The steady-state and,transient responses with different hydrogen concentrations has been measured at various temperatures. Based on. the large Schottky barrier height, and presence of oxide layer, the studied device exhibits a high hydrogen detection sensitivity and wide temperature operating regime. The studied device exhibits the. low-leakage current and obvious current changes when exposed to hydrogen-contained gas. Even at room temperature, a very. high hydrogen detection sensitivity of 155.9 is obtained when a 9090 ppm H-2/air gas is introduced. Furthermore, when exposed to hydrogen-contained gas at 95 degreesCi both the forward and reverse currents are substantially increased with, increased. hydrogen concentration. In other words,, the studied device can be used as a hydrogen sensor under the applied bidirectional bias. Under the Applied voltage of 0.35 V And 9090 ppm H2/air hydrogen ambient, a fast adsorption response time about 10 s is found. The transient and steady-state characteristics of hydrogen adsorption are also investigated.