GaO is a promising gas-sensing material that can operate over a wide temperature range. However, despite its relevance for practical applications, there is a lack of understanding regarding its sensing mechanism at temperatures below 800 °C. To reveal the sensing mechanism, GaOOH nanorods were grown on β-GaO seed layers by chemical bath deposition, then converted to β-GaO by annealing in the air at 500 °C, and the surface properties were investigated by near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) in the presence of oxidizing/reducing gases. Time-stable shifts in the XPS spectra were used to estimate the relative changes in conductivity in compliance with the ionosorption model. Our results indicate that the sensing mechanism at lower temperatures is governed by redox reactions, leading to an increase/decrease in the conductivity for reducing/oxidizing gases. Furthermore, we provide a detailed description of the ethanol-sensing mechanism at different temperatures.

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近环境压力 XPS 揭示 β-Ga2O3 纳米结构的低温气敏机制


GaO是一种很有前景的气敏材料，可以在很宽的温度范围内工作。然而，尽管它与实际应用相关，但人们对其在 800°C 以下温度下的传感机制缺乏了解。为了揭示传感机制，通过化学浴沉积在 β-GaO 种子层上生长 GaOOH 纳米棒，然后通过在 500 °C 的空气中退火将其转化为 β-GaO，并通过近环境压力 X- 研究其表面性质。氧化/还原气体存在下的射线光电子能谱 (NAP-XPS)。 XPS 光谱中的时间稳定位移用于估计符合离子吸附模型的电导率的相对变化。我们的结果表明，较低温度下的传感机制受氧化还原反应控制，导致还原/氧化气体的电导率增加/减少。此外，我们还详细描述了不同温度下的乙醇传感机制。