We present results of local spin density approximation (LSDA) pseudopotential calculations for the perovskite structure oxide, bismuth manganite (BiMnO3). The origin of the differences between bismuth manganite and other perovskite manganites is determined by first calculating total energies and band structures of the high symmetry cubic phase, then sequentially lowering the magnetic and struct...

Lithium calcium niobium oxide (2/1.5/3/10), Li(2)Ca(1.5)Nb(3)O(10), has been synthesized by conventional solid-state reaction. Its structure consists of triple-layer perovskite slabs of corner-sharing NbO(6) octa-hedra inter-leaved with lithium ions; Ca cations partially occupy the perovskite A sites at 75% occupancy probability. All eight atoms in the asymmetric unit are on special positions: ...

The potential growth modes for epitaxial growth of Fe3O4 on SrTiO3 (001) are investigated through control of the energetics of the pulsed-laser deposition growth process (via substrate temperature and laser fluence). We find that Fe3O4 grows epitaxially in three distinct growth modes: 2D-like, island, and 3D-to-2D, the last of which is characterized by films that begin growth in an island growt...

We show why and how the spin state of transition-metal ions affects the thermoelectric properties of transition-metal oxides by investigating two perovskite-related oxides. In the A-site ordered cobalt oxide Sr3YCo4O10.5, partial substitution of Ca for Sr acts as chemical pressure, which compresses the unit cell volume to drive the spin state crossover, and concomitantly changes the magnetizati...

Fluorene-free perovskite light-emitting diodes (LEDs) with low turn-on voltages, higher luminance and sharp, color-pure electroluminescence are obtained by replacing the F8 electron injector with ZnO, which is directly deposited onto the CH3NH3PbBr3 perovskite using spatial atmospheric atomic layer deposition. The electron injection barrier can also be reduced by decreasing the ZnO electron aff...

Tensile and compressive solid-solution thin films based on LaAlO3 and CaZrO3 compositions were grown on perovskite oxide substrates using pulsed laser deposition to study growth mode transitions and strain relaxation. A buried layer of SrRuO3 between the thin film and the SrTiO3 substrate was also introduced to provide an auxiliary embedded strain gauge, which helps identify the critical condit...

Cross-sections of a hole-conductor-free CH3NH3PbI3 perovskite solar cell were characterized with Kelvin probe force microscopy. A depletion region width of about 45 nm was determined from the measured potential profiles at the interface between CH3NH3PbI3 and nanocrystalline TiO2, whereas a negligible depletion was measured at the CH3NH3PbI3/Al2O3 interface. A complete solar cell can be realize...

We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show mor...

Colloidal perovskite oxide nanocrystals have attracted a great deal of interest owing to the ability to tune physical properties by virtue of the nanoscale, and generate thin film structures under mild chemical conditions, relying on self-assembly or heterogeneous mixing. This is particularly true for ferroelectric/dielectric perovskite oxide materials, for which device applications cover piezo...

Wide applications of personal consumer electronics have triggered tremendous need for portable power sources featuring light-weight and mechanical flexibility. Perovskite solar cells offer a compelling combination of low-cost and high device performance. Here we demonstrate high-performance planar heterojunction perovskite solar cells constructed on highly flexible and ultrathin silver-mesh/con...