Dopant concentration variation or solvent change is commonly used for the growth and characterization of doped metallic thin films. In contrast, we have studied the effects of varying methanol solvent volume ratio for aluminum doped zinc oxide (AZO) thin film growth. AZO thin films were coated on glass and ITO substrates by nebulizer spray pyrolysis (NSP) method. The effect of different solvent concentrations and the water to methanol ratio on the resultant film properties were analyzed. The structural and lattice constants of the prepared films were investigated by X-ray diffraction (XRD). Pure methanol solvent enhances the structural quality of the AZO film, as confirmed from the XRD and X-ray photoelectron spectroscopy (XPS) analyses. The atomic force microscopy (AFM) images showed thinner and smooth film surface for pure methanol solvent condition without water. The optical absorption study showed a high transmittance (~93%) in the visible region with bandgap of 3.30 eV, which is close to bulk ZnO (3.36 eV). The photoluminescence (PL) spectra showed a powerful UV emission at 390 nm, indicating that the films were of good quality. Ag/AZO/Cu2O/ITO structured photodiodes were fabricated using ITO substrate and their photosensing properties were studied. All the prepared films (S1, S2, S3, S4 and S5) showed an increase in current level for both dark and light conditions, with an increase in methanol solvent ratio. The film S5 (pure methanol solvent) under the dark and light illumination conditions at a bias of 1.0 V, showed current values of ~6.5×10–5 A and ~1.85×10–4A respectively.

中文翻译：

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甲醇溶剂对雾化器喷雾热解法生长的 AZO 薄膜光敏性能的影响

掺杂剂浓度变化或溶剂变化通常用于掺杂金属薄膜的生长和表征。相比之下，我们研究了不同甲醇溶剂体积比对铝掺杂氧化锌 (AZO) 薄膜生长的影响。通过雾化器喷雾热解 (NSP) 方法将 AZO 薄膜涂覆在玻璃和 ITO 基板上。分析了不同溶剂浓度和水甲醇比对所得薄膜性能的影响。通过X射线衍射（XRD）研究了制备的薄膜的结构和晶格常数。XRD 和 X 射线光电子能谱 (XPS) 分析证实，纯甲醇溶剂可提高 AZO 膜的结构质量。原子力显微镜 (AFM) 图像显示，在没有水的纯甲醇溶剂条件下，薄膜表面更薄且光滑。光吸收研究表明，在可见光区具有高透射率 (~93%)，带隙为 3.30 eV，接近块状 ZnO (3.36 eV)。光致发光 (PL) 光谱在 390 nm 处显示出强大的紫外发射，表明薄膜质量良好。使用ITO衬底制造Ag/AZO/Cu2O/ITO结构的光电二极管并研究了它们的光敏特性。随着甲醇溶剂比例的增加，所有制备的薄膜（S1、S2、S3、S4 和 S5）在黑暗和光照条件下都显示出电流水平的增加。在偏压为 1.0 V 的明暗照明条件下，薄膜 S5（纯甲醇溶剂）显示出~6.5×10-5 A 和~1 的电流值。