Transparent superconductivity in lithiated indium tin oxide thin films

Indium tin oxide (Sn-doped ${\mathrm{In}}_{2}{\mathrm{O}}_{3}$; ITO) is a well-studied transparent conductor where doping can be used to stabilize a superconducting state. In this work, we use a combination of thin film deposition of ITO and solution-phase chemistry using $n\text{-BuLi}$ (${\mathrm{C}}_{4}{\mathrm{H}}_{9}\mathrm{Li}$) to realize superconductivity in Li-doped ITO. Solution-phase intercalation is commonly employed for bulk, polycrystalline materials but has rarely been applied to thin films. Using x-ray diffraction, atomic force microscopy, electronic transport, and optical transmission measurements, we characterize the optical transparency and superconductivity of lithium intercalated ITO thin films. After 72 hours of lithium intercalation, we find a critical temperature, ${T}_{\text{c}}$, of 0.49 K and an optical transparency of at least $73%$ in the visible optical range---all while maintaining crystallinity and nanometer surface roughness.