Abstract In this investigation, thin films of molybdenum trioxide (MoO3) were deposited on a silicon substrate using the physical vapor deposition method to fabricate a Pt/MoO3/Si heterojunction Schottky diode. To study the morphological characteristics, chemical composition and crystalline phases present in the synthesized thin films, FESEM, Raman spectroscopy, and XRD pattern analysis were performed, respectively. The XRD pattern proves the formation of an α-MoO3 phase structure. Raman spectra indicate that deposited films are orthorhombic and FESEM image of the sample demonstrates the uniformly growth of thin films. The platinum and gold metals were used as the electrodes to form Schottky and ohmic contacts of the gas sensor, respectively. The fabricated sample was exposed to 0.05% up to 0.25% concentrations of Hydrogen gas at 170 to 300 °C. It is observed that the highest sensitivity of the sensor occurs at 260 °C. The response values at an optimum temperature of 260 °C were about 18% for 0.05% and 58% for 0.25% of the target gas, while the sample exhibits response and recovery times of 29 and 158 s toward 0.25% of hydrogen gas, respectively. Moreover, the Schottky barrier height of the fabricated heterojunction diode is estimated to be 0.32 eV, which confirms its rectifying behavior.

中文翻译：

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用于氢检测的高灵敏度MoO3基异质结肖特基传感器的合成和最佳温度确定

摘要 在这项研究中，使用物理气相沉积方法在硅衬底上沉积三氧化钼 (MoO3) 薄膜以制造 Pt/MoO3/Si 异质结肖特基二极管。为了研究合成薄膜中存在的形态特征、化学成分和晶相，分别进行了 FESEM、拉曼光谱和 XRD 图案分析。XRD 图证明形成了 α-MoO3 相结构。拉曼光谱表明沉积的薄膜是正交的，样品的 FESEM 图像表明薄膜的均匀生长。铂金属和金金属用作电极，分别形成气体传感器的肖特基触点和欧姆触点。制造的样品在 170 至 300 °C 下暴露于浓度为 0.05% 至 0.25% 的氢气中。据观察，传感器的最高灵敏度出现在 260 °C。在 260 °C 的最佳温度下，0.05% 目标气体的响应值约为 18%，0.25% 目标气体的响应值约为 58%，而样品对 0.25% 氢气的响应和恢复时间分别为 29 和 158 秒. 此外，所制造的异质结二极管的肖特基势垒高度估计为 0.32 eV，这证实了其整流行为。