摘要
In this paper, high-quality nanocrystalline SnO_2 thin film was grown on bare Si(100) substrates by a sol–gel method. A metal–semiconductor–metal gas sensor was fabricated using nanocrystalline SnO_2 thin film and palladium(Pd)metal. The contact between Pd and nanocrystalline SnO_2 film is tunable. Ohmic barrier contact was formed without addition of glycerin, while Schottky contact formed by adding glycerin. Two kinds of sensor devices with Schottky contact were fabricated(Device 1: 8 h, 500 °C; Device 2: 10 h, 400 °C). The room temperature sensitivity for hydrogen(H_2) was120 and 95 % in 1000 ppm H_2, and the low power consumption was 65 and 86 l W for two devices, respectively. At higher temperature of 125 °C, the sensitivity was increased to 195 and 160 %, respectively. The sensing measurements were repeatable at various temperatures(room temperature, 75, 125 °C) for over 50 min. It was found that Device 1 has better sensitivity than Device 2 due to its better crystallinity. These findings indicate that the sensors fabricated on bare Si by adding glycerin to the sol solution have strong ability to detect H_2 gas under different concentrations and temperatures.
In this paper, high-quality nanocrystalline SnO_2 thin film was grown on bare Si(100) substrates by a sol–gel method. A metal–semiconductor–metal gas sensor was fabricated using nanocrystalline SnO_2 thin film and palladium(Pd)metal. The contact between Pd and nanocrystalline SnO_2 film is tunable. Ohmic barrier contact was formed without addition of glycerin, while Schottky contact formed by adding glycerin. Two kinds of sensor devices with Schottky contact were fabricated(Device 1: 8 h, 500 °C; Device 2: 10 h, 400 °C). The room temperature sensitivity for hydrogen(H_2) was120 and 95 % in 1000 ppm H_2, and the low power consumption was 65 and 86 l W for two devices, respectively. At higher temperature of 125 °C, the sensitivity was increased to 195 and 160 %, respectively. The sensing measurements were repeatable at various temperatures(room temperature, 75, 125 °C) for over 50 min. It was found that Device 1 has better sensitivity than Device 2 due to its better crystallinity. These findings indicate that the sensors fabricated on bare Si by adding glycerin to the sol solution have strong ability to detect H_2 gas under different concentrations and temperatures.
基金
conducted under FRGS Grant:203/PFIZIK/6711197 the support from Universiti Sains Malaysia gratefully acknowledged
