Room-temperature epitaxial growth of indium tin oxide thin films on Si substrates with an epitaxial CeO₂ ultrathin buffer

Room-temperature epitaxy of indium tin oxide (ITO) thin films was achieved on Si(1 1 1) substrates with an epitaxial CeO₂ ultrathin buffer using a pulsed laser deposition technique. The epitaxial CeO₂ buffer layer was also grown at room temperature. Reflection high-energy electron diffraction and pole figure X-ray diffraction analyses confirmed the formation of a double heteroepitaxial structure of ITO(1 1 1)/CeO₂(1 1 1)/Si(1 1 1) with the epitaxial relationship of [- 110]_ITO//[- 110]_CeO2//[1-10]_Si. The junction of [ITO: 100 nm thick/CeO₂: 3 nm thick/p-Si(1 1 1)] fabricated at room temperature exhibited solar cell properties.