The pure and Cu-doped CdO thin films with various doping concentrations (0.5 to 2 wt%) were deposited on amorphous glass substrates by a chemical spray pyrolysis technique for hydrogen gas sensor application. The crystallinity, morphology, optical and electrical properties of the CdO thin films were effectively modified by Cu doping. The CdO film exhibited a cubic crystal structure, which is retained after Cu doping with significant changes in the preferential orientation of the crystallographic plane. The SEM and AFM images clearly revealed that the grain size and roughness of the CdO film changed with the Cu doping level. The expected element compositions were initially identified by EDAX and then authentically confirmed by XPS to determine its binding energy states. The optical transmittance and near band edge emission (NBE) bands of the CdO film were significantly decreased by Cu doping level. The minimum resistivity (2.01 × 10⁻³ Ω cm) as well as good mobility (19.5 cm² V⁻¹ s⁻¹) and maximum carrier concentration (1.98 × 10²⁰ cm⁻³) were obtained for the 1 and 0.5 wt% Cu-doped CdO thin films. The Cu-doped CdO thin films exhibit better hydrogen gas sensing behaviour than that of pure CdO film. Finally, it is concluded that the maximum sensitivity is vividly achieved for the Cu-doped CdO thin film at 1 wt%.

中文翻译：

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通过铜掺杂增强氧化镉薄膜的电阻型氢气传感特性

通过化学喷雾热解技术，在氢气传感器应用中，将具有各种掺杂浓度（0.5至2 wt％）的纯Cu掺杂的CdO薄膜沉积在非晶玻璃基板上。Cu掺杂可以有效地改变CdO薄膜的结晶度，形貌，光学和电学性质。CdO膜表现出立方晶体结构，在Cu掺杂后，晶体结构的优先取向发生了显着变化，从而保留了该晶体结构。SEM和AFM图像清楚地表明CdO膜的晶粒尺寸和粗糙度随Cu掺杂水平的变化而变化。预期的元素组成首先由EDAX鉴定，然后由XPS真实地确定以确定其结合能状态。CdO薄膜的光透射率和近带边缘发射（NBE）谱带由于Cu掺杂水平而显着降低。最小电阻率（2.01×10^-3以及良好的流动性（19.5厘米Ω厘米） ² V ^-1小号^-1）和最大载流子浓度（1.98×10 ²⁰厘米^-3）为1和0.5重量％的Cu掺杂的氧化镉的薄膜得到的。铜掺杂的CdO薄膜表现出比纯CdO薄膜更好的氢气感测行为。最后，得出的结论是，在1 wt％的情况下，掺杂Cu的CdO薄膜生动地实现了最大灵敏度。