Structural and optoelectronic properties of combining Nb-doped SrTiO3/ITO films on (0 0 1)-YSZ substrate

Abstract Functional oxides combined with conventional conductive films are competitive alternative candidates as electrode and electron transport layer. This work explored the film and interface structures and the optoelectronic properties of the combined films of Nb-doped SrTiO3 (Nb-STO) as a classical functional oxide and ITO. The combined films were deposited on a (0 0 1)-YSZ substrate via laser molecular beam epitaxy method. In-situ high-energy electron diffraction, X-ray diffraction, and transmission electron microscopy shew [0 1 1]Nb-STO azimuth orientation and a two-fold symmetry rotation of the Nb-STO layer. Interestingly, the Nb-STO film growth at 650 °C or higher was able to induce cracks in ITO film. Besides, the growth temperature of Nb-STO from 400 °C to 700 °C changed its structures from amorphousness to polycrystal, the Nb-STO/ITO interface relationships, sheet resistance (from 25 to 83 Ω/sq) and electron mobility (40 to 2 cm·V−1·s−1); however, this had little influence on the transmittance. This work provided an insight into the combination of functional oxides and ITO for the fabrication of the electron transport layer.