Resonant photoemission of single crystals of the double perovskites GdBaCo2O5+d and DyBaCo2O5+d has been carried out at the UK Synchrotron Radiation Source at Daresbury. The resonance onset energy at the Co 3p→3d threshold is used to explore the Co spin state in the double perovskites as a function of temperature. In contrast with the simple perovskites LaCoO3 and HoCoO3, an undelayed resonance...

Organo lead mixed -ha l ide perovsk i t e s such as CH3NH3PbX3−aX′a (X, X′ = I, Br, Cl) are interesting semiconductors because of their low cost, high photovoltaic power conversion efficiencies, enhanced moisture stability, and band gap tunability. Using a combination of optical absorption spectroscopy, powder X-ray diffraction (XRD), and, for the first time, Pb solid state nuclear magnetic res...

Lead-free organic-inorganic tin halide perovskites were prepared and investigated by a rapid screening technique utilizing a modified scanning electrochemical microscope (SECM). We studied liquid junction photoelectrochemical (PEC) solar cells based on p-type methylammonium tin halide (MASnI3-xBrx) perovskites employing the benzoquinone (BQ) redox couple, BQ/BQ , in dichloromethane (CH2Cl2). We...

ABO3 perovskites with small cations at the A site (A = Sc(3+), In(3+) and Mn(2+) and B = Al(3+) and transition metals) are reviewed. They extend the corresponding families of perovskites with A(3+) = Y, La-Lu, and Bi and A(2+) = Cd, Ca, Sr and Ba and exhibit the largest structural distortions. As a result of these large distortions, they show, in many cases, distinct structural and magnetic pro...

Perovskite and related Ruddlesden-Popper type transition metal oxides synthesised at high pressures and temperatures during the last decade are reviewed. More than 60 such new materials have been reported since 1995. Important developments have included perovskites with complex cation orderings on A and B sites, multiferroic bismuth-based perovskites, and new manganites showing colossal magneto...

Many years since the booming of research on perovskite solar cells (PSCs), the hybrid perovskite materials developed for photovoltaic application form three main categories since 2009: (i) high-performance unstable lead-containing perovskites, (ii) low-performance lead-free perovskites, and (iii) moderate performance and stable lead-containing perovskites. The search for alternative materials t...

Perovskites are attractive redox materials for thermo/electrochemical fuel synthesis. To design perovskites with balanced redox energetics for thermochemically splitting CO2, the activity of lattice oxygen vacancies and stability against crystal phase changes and detrimental carbonate formation are predicted for a representative range of perovskites by electronic structure computations. Systema...

Cation-exchangeable d(0) layered perovskites are amenable to intercalation, exfoliation, and a variety of topochemical reactions, but they lack the interesting electronic and magnetic functionalities of mixed-valent perovskites. Conversely, electronically and magnetically interesting layered perovskites lack scope in terms of interlayer chemistry. To bridge this gap, the insulating, cation-exch...

the synthesis of nb doped batio3 has been investigated under microwave-hydrothermal (mh) conditions in the temperature of 150°c for only 2 h using c16h36o4ti, bah2o2.8h2o and nbcl5 as ba, ti and  nb sources, respectively.  typical experiments performed on mh processing have not yet reported for nb doped batio3.  in the mh process, the formation of high purity nano tetragonal nb-batio3 was stron...

A new route for fabrication of photoactive materials in organic-inorganic hybrid solar cells is presented in this report. Photoactive materials by blending a semiconductive conjugated polymer with an organolead halide perovskite were fabricated for the first time. The composite active layer was then used to make planar heterojunction solar cells with the PCBM film as the electron-acceptor. Phot...