The present report focuses on, comparative study of the phosphotungstic acid (H₃PW₁₂O₄₀) (PTA) and cesium (Cs⁺) ion-doped phosphotungstic acid (Cs₃PW₁₂O₄₀) (Cs-PTA) nanocrystalline thin films via facile hydrothermal route. The synthesized PTA and Cs-PTA thin films were characterized for their optostructural, morphological, compositional, electrical, and photoelectrochemical properties. The optical absorption study revealed that direct allowed type of electronic transition with decrease in band gap energy from 3.24 to 2.94 eV as a function of Cs⁺ ion concentration in Cs-PTA thin films. A structural study shows that the synthesized PTA and Cs-PTA thin films were polycrystalline in nature with the formation of a spinel cubic crystal structure. Morphology of the deposited Cs-PTA films illustrates the formation of dense, uniform nanosphere like morphology. The high-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED) study confirm the formation of polycrystalline nature of the Cs-PTA thin films. Compositional analysis demonstrates that stoichiometric film formation with valence states of Cs⁺, O²⁻, W⁶⁺, and P⁵⁺ was existed in the Cs-PTA films. The electrical measurement (EC) study shows semiconducting behavior with p-type in nature. Current density–voltage (J–V) measurement demonstrates that Cs-PTA thin films shows boost in PEC performance with photoconversion efficiency of 2.20%.

本报告重点研究磷钨酸（H ₃ PW ₁₂ O ₄₀）（PTA）和铯离子（Cs ⁺）掺杂的磷钨酸（Cs ₃ PW ₁₂ O ₄₀）（Cs-PTA）纳米晶薄膜的比较研究。通过方便的热液路线。合成的PTA和Cs-PTA薄膜的光学结构，形态，组成，电学和光电化学特性对其进行了表征。光吸收研究表明，直接允许的电子跃迁类型随着Cs ^{+的变化而}从3.24 eV的带隙能量减小Cs-PTA薄膜中的离子浓度。结构研究表明，合成的PTA和Cs-PTA薄膜本质上是多晶的，形成了尖晶石立方晶体结构。沉积的Cs-PTA膜的形态说明了致密，均匀的纳米球状形态的形成。高分辨率透射电子显微镜（HR-TEM）和选择区域电子衍射（SAED）研究证实了Cs-PTA薄膜的多晶性质。组成分析表明，在Cs-PTA膜中存在具有Cs ⁺，O ²⁻，W ⁶⁺和P ⁵⁺价态的化学计量成膜。电学测量（EC）显示半导体行为为p类型的性质。电流密度-电压（J–V）测量表明，Cs-PTA薄膜显示出PEC性能的提高，光转换效率为2.20％。