| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 98 === Si0.72Ge0.28 thin films of 550 nm were deposited on the quartz glass substrate by RF magnetron sputter. The films were ion implanted with boron at dosages between 5×1012 and 1×1015 cm-2, then crystallized by rapidly thermal annealed at 700 °C for 1 minute. Boron ([B]=2.3×1019 cm-3) doped Si0.72Ge0.28 thin films shows a conductivity of 8.63×10-6 /Ωcm, a carrier concentration of 6.33×1011 cm-3, a carrier mobility of 2.14×102 cm2/Vs, a maximum Seebeck coefficient of 124.67 mV/K, a maximum power factor of 1.34×10-5 W/K2m. We found that the conductivity increased, carrier concentration increased, carrier mobility decreased, and Seebeck coefficient increased with increased the boron concentration of Si0.72Ge0.28 thin films. In this report, carbon fiber cloth was utilized as a support for the Pt catalyst in the thermoelectric hydrogen sensor. The sensor with Si0.72Ge0.28 thin films annealed at 700 °C for 1 minute operating at 100 °C detected hydrogen in air at concentration from 0.1 to 1%, and showed a catalyst activity of 21.9 °C, 15.6 °C, and 11 °C. A response time corresponding to 90% voltage single about 54s in hydrogen concentration of 1%.
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