Structural and electrical properties of transparent conductor SrVO3 thin films grown using radio frequency sputtering deposition

Transparent conductor SrVO3 thin films were grown on (LaAlO3)(0.3)(Sr2AlTaO6)(0.7) (LSAT), SiO2/Si, LaAlO3, and sapphire substrates using RF magnetron sputtering deposition with commercial SrVO3 targets at temperatures as low as 400 degrees C. Considering the complex phases of SrVO3 material systems, the growth temperature and sputtering gases were optimized and precisely controlled to yield a transparent and conductive SrVO3 phase. The authors used a mixed gas atmosphere of Ar and H-2 during growth for reduction. Structural and morphological properties of all SrVO3 films were investigated using x-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and scanning electron microscopy. XRD and HRTEM showed a highly crystalline cubic phase of SrVO3 films. In addition, HRTEM showed that a superstructure along the [100] direction could be formed due to Jahn-Teller distortion in the cubic phase of SrVO3 films. The authors obtained a resistivity of 0.2 x 10(-3) Ocm, mobility of 1.82 cm(2)/(V s), and carrier concentration of 1.57 x 10(22) cm(-3) for SrVO3/LSAT films. Optical transmittance was measured as 88% at a photon wavelength of 633 nm for 39-nm-thick SrVO3 films. Using x-ray photoemission spectroscopy (XPS) and its depth profile analysis, the authors investigated chemical compositions and binding energies of Sr, V, and O atoms in SrVO3 films, and their depth profiles. The authors found a correlation between the resistivities and XPS binding energy spectra for SrVO3 films as functions of film thickness and substrates. Published by the AVS.