Abstract Transparent amorphous Li 2.5 TaO x thin films with different thicknesses were deposited by RF magnetron sputtering. The ionic conductivities of as-deposited films determined by ac impedance spectroscopy were of the order of 10 −8 S/cm at room temperature. The surface roughness increased rapidly with the film thickness increasing as confirmed by scanning electron microscopy and atomic force microscopy. Inorganic monolithic electrochromic devices (ECDs) based on WO 3 //NiO complementary structure were fabricated using the Li 2.5 TaO x with different thicknesses as the ion conductor layers. The electro-optical performance of the ECDs was characterized by cyclic voltammetry and chronoamperometry. The ECDs showed a highest optical modulation of 40% at 550 nm driven by − 1.5 V (coloration) and 1 V (bleaching) with switching time of 30 s. Both the amount of transferred charge and coloration efficiency were found to be highly dependent on the film thickness of Li 2.5 TaO x layer. The high charge transfer resistance at the Li 2.5 TaO x /WO 3 interface and poor growth of WO 3 layer due to the high surface roughness of Li 2.5 TaO x may well account for the decreased device performance.

中文翻译：

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溅射Li 2.5 TaO x 离子导体的厚度依赖表面粗糙度及其对无机单片电致变色器件电光性能的影响

摘要 采用射频磁控溅射法制备了不同厚度的透明非晶Li 2.5 TaO x 薄膜。通过交流阻抗谱测定的沉积膜的离子电导率在室温下约为 10 -8 S/cm。扫描电子显微镜和原子力显微镜证实，表面粗糙度随着膜厚度的增加而迅速增加。使用具有不同厚度的Li 2.5 TaO x 作为离子导体层制造了基于WO 3 //NiO互补结构的无机单片电致变色器件(ECD)。ECD 的光电性能通过循环伏安法和计时电流法表征。ECD 在 550 nm 处显示出 40% 的最高光学调制，由 - 1.5 V（着色）和 1 V（漂白）驱动，切换时间为 30 秒。发现转移的电荷量和着色效率都高度依赖于Li 2.5 TaO x 层的膜厚度。Li 2.5 TaO x /WO 3 界面处的高电荷转移电阻和由于Li 2.5 TaO x 的高表面粗糙度导致的WO 3 层生长不良很可能是器件性能下降的原因。