Development of Noble Metal-Gate TiO_2 Schottky Diode DH sensor

研究了氢敏感金属栅肖特基势垒二极管在溶解氢传感器中的应用。采用nb_2o_5掺杂TiO_2单晶和pd基合金（Pd-Ag, Pd-Au, Pd-Pt）薄膜分别作为半导体和二极管的催化金属栅。首先在298K下不同DH浓度的水溶液中检测了二极管的DH响应。结果表明，Pd-30-40at%Ag合金栅极二极管在较宽的浓度范围内对DH具有较高的灵敏度。它们在298K时不会发生氢脆，并且在高温下具有良好的耐腐蚀性。在1298 ~ 573k范围内，Pd-30-40at%Ag二极管的响应电压与溶液DH浓度呈线性关系。二极管对pH的灵敏度小于其对DH的灵敏度的10%。该二极管表现出良好的长期稳定性，但在高温溶液中长时间暴露后，其DH响应率下降。

An application of hydrogen-sensitive metal-gate Schottky barrier diodes to dissolved hydrogen (DH) sensors was examined. Single crystals of Nb_2O_5-doped TiO_2 and thin films of Pd-base alloy (Pd-Ag, Pd-Au, Pd-Pt) were used as a semiconductor and a catalytic metal-gate of diodes, respectively. The DH response of the diodes was first examined in aqueous solutions with various DH concentrations at 298K.It was found that Pd-30-40at%Ag alloy-gate diodes showed a high sensitivity to DH over a wide concentration range. They did not suffer from hydrogen embrittlement at 298K and had a good corrosion resistance at elevated temperatures. Linear relationships between the response voltage of Pd-30-40at%Ag diodes and the DH concentration of solutions were found at every temperatures examined (1298-573K) . The sensitivities of the diodes to pH were less than 10% of their sensitivities to DH.The diodes showed good long-term stability, while their DH response rate decreased after prolonged exposure in high-temperature solutions.