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BaSn1−xTixO3 (BSTO, x = 0, 0.25, 0.5, 0.75, 1.0) epitaxial films were deposited on LaAlO3(001) substrates by employing a pulsed laser deposition system. Their composition dependent structure and optical properties were systematically investigated using density functional theory (DFT) calculations. High resolution x-ray diffraction characterization showed that the film lattice parameters decrease linearly with the increase in Ti concentrations, following Vegard's law. Optical property measurements revealed that all films have the optical transmittance of more than 70% in the visible and infrared wavelength range. Interestingly, the bandgap nonlinearity of BSTO films was observed, and the film at Ti doped x = 0.25 has the largest bandgap value of 4.04 eV. The calculated electronic structure and the density of states of BSTO films determined by DFT suggested that the strong hybridization between Sn 5s and Ti 3d orbitals caused the initial expansion of the bandgap, whereas upon further increasing the doping content, Ti 3d orbitals dominated the conduction band, leading to the bandgap reduction. [ABSTRACT FROM AUTHOR]

Perovskite-structured (Sm x Sr 1- x)SnO 3 (SSSO) films with x = 0–0.15 were epitaxially grown on LaAlO 3 (001) substrates by pulsed laser deposition, and the microstructure, transport and optical properties were investigated in detail. X-ray diffraction results show that the lattice constants gradually decrease with the Sm content increasing. Atomic force microscopy images confirm that all the films possess a smooth surface with low surface roughness. X-ray photoelectron spectroscopy measurements prove the existence of Sm3+ state in the doped SSSO films. Hall-effect measurements show that the film at x = 0.06 has the lowest room-temperature resistivity of 5.91 mΩcm and the highest electron mobility of 14.8 cm2/Vs. Temperature-dependent resistivity curves were fitted and explained by weak localization effect and e -- e - interactions at low temperatures for films at x = 0.04 to 0.10. Optical transparency of all the films is more than 70% in the wavelength range from 600 to 1800 nm, and the band gaps increase gradually from 4.27 to 4.60 eV with increasing Sm content to 0.06, which can be ascribed to Burstein-Moss effect. Furthermore, the insertion of pure SrSnO 3 buffer layer between the substrate and the SSSO film considerably reduces the density of dislocations, thereby leading to the improved electrical transport property. All these results bring rare-earth element Sm a step closer to optoelectronic applications of all-perovskite transparent and conductive oxides. The transparent and conductive Sm-doped SrSnO 3 thin films were prepared. For comparison, a SrSnO 3 buffer layer was inserted between the film and the substrate. Image 1 • Transparent conducting Sm-doped SrSnO 3 films were prepared by pulsed laser deposition. • The film at x = 0.06 has the lowest room-temperature resistivity of 5.91 mΩcm and the highest mobility of 14.8 cm2/V. • The electrical conductivity is enhanced greatly with the insertion of SrSnO 3 buffer layer. [ABSTRACT FROM AUTHOR]

Nb-doped SrSnO3 (SSNO) thin films were epitaxially grown on LaAlO3(001) single-crystal substrates using pulsed laser deposition under various oxygen pressures and substrate temperatures. The crystalline structure, electrical, and optical properties of the films were investigated in detail. X-ray diffraction results show that the cell volume of the films reduces gradually with increasing oxygen pressure while preserving the epitaxial characteristic. X-ray photoelectron spectroscopy analysis confirms the Nb5+ oxidation state in the SSNO films. Hall-effect measurements were performed and the film prepared at 0.2 Pa with the 780 °C substrate temperature exhibits the lowest room-temperature resistivity of 31.3 mΩcm and Hall mobility of 3.31 cm2/Vs with a carrier concentration at 6.03 × 1019/cm3. Temperature-dependent resistivity of this sample displays metal-semiconductor transition and is explained mainly by electron-electron effects. Optical transparency of the films is more than 70% in the wavelength range from 600 to 1800 nm. The band gaps increase from 4.35 to 4.90 eV for the indirect gap and 4.82 to 5.29 eV for the direct by lowering oxygen pressure from 20 to 1 × 10−3 Pa, which can be interpreted by Burstein-Moss effect and oxygen vacancies generated in the high vacuum. [ABSTRACT FROM AUTHOR]

• Thin films based on Li-doped Zn 0.4 Ni 0.6 -δ ≏ δ O ceramic were successfully prepared. • Thin films with high Ni/Zn atom ratio still maintain the rock-salt structure. • The structure, optical, electrical properties and Li-ionic storage were investigated. • Li-doped Zn 0.4 Ni 0.6 -δ ≏ δ O films exhibit the prospect of multifunctional applications. Nanostructured (Zn 0.4 Ni 0.6 - δ ◻ δ) 0.95 Li 0.05 O thin films were successfully prepared by radio frequency magnetron sputtering. The multifunctional properties such as optical, thermal sensitivity and Li-storage of the thin films were investigated. The prepared thin films maintain a rock-salt phase, have a wide optical band gap of 3.77 eV, and show typical negative temperature coefficient (NTC) of resistivity. The thin film also delivers a high reversible specific capacity of 797 mAh g−1 after 100 cycles at 200 mA g−1 for application of an electrode in Li-ion batteries. This work provides potential functional applications in the fields of photoelectric devices, thermal sensors and new energy devices. [ABSTRACT FROM AUTHOR]

(a) Sketches for SnO 6 octahedron of LSSO under bulk and in-plane compressive strain state. (b) The strain diagram and variation of metal-semiconductor transition temperature as a function of strain imposed by substrates for LSSO(001) and LSSO(011) epitaxial films. (c) The charge density contours of (001)-plane and (011)-plane of LSSO calculated by DFT. [Display omitted] • The epitaxial La 0.05 Sr 0.95 SnO 3 /LaAlO 3 films were fabricated by pulsed laser deposition. • Both (0 0 1) and (0 1 1) heterostructure films show 80 % high optical transmittance. • Both (0 0 1) and (0 1 1) heterostructure films show a good conductivity. • The higher mobility due to the in-plane strain decrease was testified by DFT. We have studied the structural, electrical, and optical properties of La 0.05 Sr 0.95 SnO 3 thin films, which exhibited a strong dependence upon the substrate's orientation and strain. X-ray diffraction results show that the LSSO films grow epitaxially on (0 0 1) and (0 1 1)-oriented LaAlO 3 substrates, and the in-plane compressive strain decreases gradually upon increasing film thickness. Room-temperature resistivity varies from 4.23 (13.0) to 1.37 (4.76) mΩ cm as the film thickness increases for (0 0 1) orientation ((0 1 1) orientation). Temperature dependent resistivity curves of all the samples show a metal–semiconductor transition (MST), which can be explained by the electron–electron interactions below MST rather than weak localization. Both reducing the in-plane compressive strain and transferring the orientation from (0 1 1) to (0 0 1) can drive the MST point shifts toward lower temperature, indicative of the enhancement of the metallic transport in the films. The band gap increases upon increasing film thickness due to Burstein-Moss effect. The charge distributions of Sn and O from density functional theory (DFT) calculations illustrate that (0 0 1)-plane has a better conductivity. Furthermore, our DFT results also demonstrate that decreasing the in-plane strain will lead to a smaller electron effective mass, thus the increased carrier mobility can be obtained. These comprehensive investigations advance our knowledge of the optoelectronic characteristics and provide valuable insights for future research in related transparent materials. [ABSTRACT FROM AUTHOR]