Vertically aligned nanocomposite films by self‐assembled epitaxial nucleation for super‐broadband transparent conductors

Abstract

Designing super‐broadband transparent conductors is challenging because of the exclusive nature of conductivity and infrared transmittance. Here, using a one‐step process, we created vertically aligned nanocomposite conducting films with high transparency across a super‐broad wavelength range. Vertically aligned transparent Ba3V2O8 nanocolumns with lateral ~100‐nm widths enable high transmittance (>50%, even at a 4‐μm wavelength) for all incident light and outperform that of Sn‐doped In2O3, while the conducting SrVO3 matrix retains low resistivity (<0.56 mΩ cm at room temperature). A combined study of scanning transmission electron microscopy, scattering scanning near‐field infrared microscopy, and X‐ray diffraction revealed that spontaneous phase separation of Ba3V2O8 nanocolumns in a SrVO3 matrix film occurs via self‐assembled epitaxial nucleation. Our vertically aligned nanocomposite films provide a fertile platform for next‐generation optoelectronics.