Large-scale, high-transparency, ultra-thin ITO membranes with robust conductivity and flexibility

Ultra-thin ITO films exhibit excellent optical properties but poor electrical properties, which greatly limit further applications in the field of optoelectronic devices. In this study, a large-area (4 inches) ITO thin film with a thickness of 10 nm was prepared on a flexible Mica substrate. The film shows low resistivity (1.32×10−4 Ω·cm), high carrier concentration (2.2 × 1021 cm−3), high optical transparency (>98.1%), and an atomic-level flat surface. XPS characterization and first principles calculations prove that the van der Waals interface between ITO and Mica can induce a higher concentration of oxygen vacancies in the ultra ITO thin film, which is the reason for its remarkable conductivity enhancement. In addition, the ITO/Mica flexible film exhibits excellent durability and recyclability, maintaining its photoelectric properties at a high bending radius of 2.5 mm and tens of thousands of bending cycles. This study will provide an important experimental basis for the further development and application of large-area, ultra-thin ITO films in flexible transparent electronic devices.