Electrochromic tungsten oxide (WO3) films suffer from gradual performance degradation during repeated ion insertion/extraction processes, while the relationship between electrolyte-dependent ion accommodation and structural stability remains insufficiently understood. Herein, magnetron-sputtered WO3 thin films were systematically investigated in H2SO4, LiClO4, ZnSO4, and Al2(SO4)3 electrolytes to clarify the coupling relationship among ion accommodation, electronic structure evolution, microstructural retention, and electrochromic durability. Combined electrochemical measurements with UV–visible spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and reflected electron energy loss spectroscopy (REELS) reveal that electrolyte chemistry regulates the balance between electrochemical activation and structural tolerance. Highly mobile H+ and strongly interacting Al3+ ions promote rapid ion transport and enhanced W6+ reduction but may induce excessive structural perturbation, defect accumulation, and accelerated degradation during cycling. Zn2+ exhibits intermediate behavior, whereas Li+ enables balanced ion accommodation through reversible W6+/W5+ conversion while preserving the WO3 framework. Consequently, the LiClO4 electrolyte achieves superior electrochromic performance with an optical modulation of 80.97% and improved cycling stability. These results demonstrate that durable electrochromic behavior is governed not by maximizing ion transport or reduction degree, but by achieving a reversible ion accommodation regime compatible with the structural tolerance of the host framework. This work provides a microstructure-oriented strategy for designing stable WO3-based electrochromic devices through electrolyte regulation.
This study investigates the optimization of RF sputtering power for high-performance ITZO TFTs by correlating the film physicochemical properties, oxygen-related defects, and device characteristics. The films were used as the channel layer in thin-film transistors (TFTs). XRD, UV–Vis spectroscopy, and XPS were systematically used to investigate the effects of sputtering power on the film structure, optical properties, chemical composition, and electrical performance of the devices. The results show that X-ray diffraction (XRD) analysis revealed that the ITZO films prepared at different sputtering powers were predominantly amorphous in structure. UV–Vis measurements indicated that the ITZO films maintained a high optical transmittance (>85%), demonstrating their strong potential for application in transparent electronic devices. X-ray photoelectron spectroscopy (XPS) analysis further showed that the sputtering power affected the chemical states of In, Sn, Zn, and O elements, as well as the concentration of oxygen vacancies in the films. Appropriately increasing the sputtering power was found to help regulate the carrier concentration and defect states of the films. When the sputtering power was 70 W, the ITZO TFT exhibited superior electrical performance, with a saturation mobility of 8.46 cm2·V−1·s−1, a threshold voltage of 1.86 V, a subthreshold swing of 0.29 V/decade, and an on/off current ratio of 4.50 × 109.
Electrochemical exfoliation is an efficient approach for producing MoS2 nanosheets, yet the correlation between exfoliation conditions, structural evolution, and nonlinear optical (NLO) properties remains insufficiently understood. In this work, MoS2 nanosheets were prepared using two representative electrolyte systems, acetonitrile/TPABr and aqueous Na2SO4, under controlled voltages. The results reveal distinct exfoliation mechanisms, where ion intercalation dominates in the nonaqueous system, while bubble-assisted processes prevail in the aqueous system. Structural and chemical analyses (Raman, XRD, EDS, and XPS) demonstrate that the nonaqueous system yields MoS2 with higher crystallinity and lower oxidation degree, whereas the aqueous system shows increased oxidation with the coexistence of Mo5+ and Mo6+ species. Correspondingly, enhanced nonlinear absorption and optical limiting performance are observed. A clear mechanism–structure–property relationship is established, highlighting the critical role of electrolyte environment and applied voltage in tailoring NLO responses. This work provides insights into the controlled preparation of MoS2 nanosheets for photonic and optoelectronic applications.