We report the synthesis and photoelectrochemical assessment of phase pure tetragonal matlockite structured BiOX (where X = Cl, Br, I) films.

Optical ultrasound transducers were created by coating optical fibres with a composite of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS). Dissolution of CNTs in PDMS to create the composite was facilitated by functionalisation with oleylamine. Composite surfaces were applied to optical fibres using dip coating. Under pulsed laser excitation, ultrasound pressures of 3.6 MPa and 4.5 MPa at the coated end faces were achieved with optical fibre core diameters of 105 and 200 μm, respectively. The results indicate that CNT-PDMS composite coatings on optical fibres could be viable alternatives to electrical ultrasound transducers in miniature ultrasound imaging probes.

This paper reports the synthesis of highly conductive niobium doped titanium dioxide (Nb:TiO 2 ) fi lms from the decomposition of Ti(OEt) 4 with dopant quantities of Nb(OEt) 5 by aerosol-assisted chemical vapor deposition (AACVD). Doping Nb into the Ti sites results in n -type conductivity, as determined by Hall effect measurements. The doped fi lms display signifi cantly improved electrical properties compared to pristine TiO 2 fi lms. For 5 at.% Nb in the fi lms, the charge carrier concentration was 2 × 10 21 cm −3 with a mobility of 2 cm 2 V -1 s -1 . The corresponding sheet resistance is as low as 6.5 Ω sq -1 making the fi lms suitable candidates for transparent conducting oxide (TCO) materials. This is, to the best of our knowledge, the lowest reported sheet resistance for Nb:TiO 2 fi lms synthesized by vapour deposition. The doped fi lms are also blue in colour, with the intensity dependent on the Nb concentration in the fi lms. A combination of synchrotron, laboratory and theoretical techniques confi rmed niobium doping into the anatase TiO 2 lattice. Computational methods also confi rmed experimental results of both delocalized (Ti 4+ ) and localized polaronic states (Ti 3+ ) states. Additionally, the doped fi lms also functioned as photocatalysts. Thus, Nb:TiO 2 combines four functional properties (photocatalysis, electrical conductivity, optical transparency and blue colouration) within the same layer, making it a promising alternative to conventional TCO materials.

Molybdenum-doped indium oxide (IMO) thin films prepared by aerosol-assisted chemical vapor deposition (AACVD) show significantly improved charge carrier mobilities as compared to nominally undoped films prepared by the same technique. The basis for this very unusual behavior has been investigated by density functional theory calculations using a hybrid Hamiltonian, mobility modeling, X-ray photoemission, and X-ray absorption spectroscopies. In contrast to previous claims that Mo acts as a three-electron donor, it is shown that substitutional Mo traps two electrons in localized states falling within the bulk bandgap and thus Mo is a simple one-electron donor. At the same time, there is very little hybridization of Mo 4d states with In 5s states at the bottom of the conduction band. This results in conduction that is spatially separated to some degree from the donors, giving rise to significantly reduced ionized impurity scattering, enhancing the carrier mobility. This is in contrast to Sn-doped In2O3 where the conduction band minimum has significant Sn 5s character, resulting in regular ionized impurity scattering.