Synthesis, Crystal Structure and Properties of a Perovskite-Related Bismuth Phase, (NH4)3Bi2I9

Organic-inorganic halide perovskites, especially methylammonium lead halide, have recently led to a remarkable breakthrough in photovoltaic devices. However, due to the environmental and stability concerns of the heavy metal, lead, in these perovskite based solar cells, research in the non-lead perovskite structures have been attracting increasing attention. In this study, a layered perovskite-like architecture, (NH4)3Bi2I9, was prepared in solution and the structure was solved by single crystal X-ray diffraction. The results from DFT calculations showed the significant lone pair effect of the bismuth ion and the band gap was measured as around 2.04 eV, which is lower than the band gap of CH3NH3PbBr3. Conductivity measurement was also performed to examine the potential in the applications as an alternative to the lead containing perovskites

Defects and disorder in metal organic frameworks.

The wide-ranging properties of metal organic frameworks (MOFs) rely in many cases on the presence of defects within their structures and the disorder that is inevitably associated with such defects. In the present work we review several aspects of defects in MOFs, ranging from simple substitutional defects at metal cation or ligand positions, to correlated defects on a larger length scale and the extreme case of disorder associated with amorphous MOFs. We consider both porous and dense MOFs, and focus particularly on the way in which defects and disorder can be used to tune physical properties such as gas adsorption, catalysis, photoluminescence, and electronic and mechanical properties.The authors would like to thank Ras Al Khaimah Center for Advanced Materials (AKC, TDB), Trinity Hall (TDB), and the ERC (ALG, Grant 279705).This is the author accepted manuscript. The final version is available from RSC via http://dx.doi.org/10.1039/C5DT04392

Oxide phosphors for light upconversion; Yb3+ and Tm3+ co-doped Y2BaZnO5

Copyright 2011 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Journal of Applied Physics 109, 063104 (2011) and may be found at

Amorphous metal-organic frameworks for drug delivery.

We report the encapsulation of the hydrophilic model molecule calcein in the Zr-based MOF UiO-66, followed by amorphization of the framework by ball-milling. We show controlled release of calcein over more than 30 days, compared with the 2 day release period from crystalline UiO-66.C.A.O. thanks Becas Chile and the Cambridge Trust for funding. T.D.B. thanks Trinity Hall (University of Cambridge) for funding. D.F.-J. thanks the Royal Society (UK) for funding through a University Research Fellowship. A.K.C is grateful to the European Research Council for an Advanced Investigator Award.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry at http://dx.doi.org/10.1039/C5CC05237