Tuning Superconductivity and Transparency via Oxygen Vacancies in Indium Tin Oxide

The fundamental challenge in integrating photonic and superconducting functionalities lies in the coexistence of superconductivity and high optical transparency on a single chip. Indium-tin oxide (ITO) films offer a promising platform spanning the visible, near-infrared (NIR), and mid-IR spectral regions. Understanding the key factors that balance these fundamental properties is essential for advancing related device technologies. Engineering of oxygen deficiency in transparent oxide conductors provides a viable route toward transparent superconductivity with tailored electronic and optical properties. Using density functional theory (DFT), we modeled oxygen-deficient surface states in reduced ITO films. The simulations reveal that the most favorable mechanism for inducing surface superconductivity involves the removal of oxygen atoms from the film surface, which flattens the electronic bands near the Fermi level.