Browsing Chemistry (Scholarly Publications) by Author "WATSON, GRAEME"
Now showing items 1-20 of 40
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Acceptor Levels in p-Type Cu2O: Rationalizing Theory and Experiment
WATSON, GRAEME; SCANLON, DAVID (2009)Understanding conduction in Cu2O is vital to the optimization of Cu-based p-type transparent conducting oxides. Using a screened hybrid?density-functional approach we have investigated the formation of p-type defects in ... -
Band gap engineering of In2O3 by alloying with Tl2O3
WATSON, GRAEME (2013)Efficient modulation of the bandgap of In 2 O 3 will open up a route to improved electronic properties. We demonstrate using ab initio calculations that Tl incorporation into In 2 O 3 reduces the band gap and ... -
Ceria co-doping: Synergistic or average effect?
WATSON, GRAEME (2014)Ceria (CeO2) co-doping has been suggested as a means to achieve ionic conductivities that are significantly higher than those in singly doped systems. Rekindled interest in this topic over the last decade has given rise ... -
Charge localization increases chemical expansion in cerium-based oxides
WATSON, GRAEME; MARROCCHELLI, DARIO (2012)In this work, we demonstrate the mechanism by which electronic charge localization increases the chemical expansion coefficient in two model systems, CeO 2-? and BaCeO 3-?. Using Density Functional Theory calculations, we ... -
Comparative study of bandwidths in copper delafossites from x-ray emission spectroscopy
WATSON, GRAEME; SCANLON, DAVID (2009)The widths of the valence bands in the copper (I) delafossites CuGaO2, CuInO2, and CuScO2 have been measured by O?K-shell x-ray emission spectroscopy and are compared with previous experimental work on CuAlO2 and CuCrO2. ... -
Comparison of the defective pyrochlore and ilmenite polymorphs of AgSbO3 using GGA and hybrid DFT
SCANLON, DAVID; WATSON, GRAEME; ALLEN, JEREMY (2011)Silver antimonate, AgSbO3, in both its defective pyrochlore and ilmenite structural polymorphs, has been suggested as a possible candidate mixed metal oxide for use in the photocatalytic splitting of water in visible light. ... -
Computational testing of trivalent dopants in CeO2 for improved high-kappa dielectric behaviour
WATSON, GRAEME (2013)Due to its high dielectric constant, large band gap, and very small lattice mismatch with Si, CeO 2 has been proposed as a promising candidate high- k dielectric material. The performance of CeO 2 as a dielectric material, ... -
Convergence of density and hybrid functional defect calculations for compound semiconductors
WATSON, GRAEME (2013)Recent revisions of defect formation energy calculations based on bandgap corrected hybrid functionals have raised concerns about the validity of earlier results based on standard density functionals and about the reliability ... -
Cu3MCh3 (M = Sb, Bi; Ch = S, Se) as candidate solar cell absorbers: Insights from theory
WATSON, GRAEME (2013)As the thin film photovoltaic sector continues to expand, there is an emerging need to base these technologies on abundant, low cost materials in place of the expensive, rare, or toxic elements such as Te, In, or Cd that ... -
A dipole polarizable potential for reduced and doped CeO(2) obtained from first principles.
WATSON, GRAEME (2011)In this paper we present the parameterization of a new interionic potential for stoichiometric, reduced and doped CeO2. We use a dipole polarizable potential (DIPPIM: the dipole polarizable ion model) and optimize its ... -
Electronic structure of mixed-valence silver oxide AgO from hybrid density-functional theory
WATSON, GRAEME; SCANLON, DAVID; ALLEN, JEREMY; SCANLON, DAVID (2010)Mixed-valence AgO has attracted attention due to its utility in battery technologies. Despite this, a nanoscopic understanding of its electronic structure has been lacking and there has been considerable controversy about ... -
The electronic structure of silver orthophosphate: Experiment and theory
WATSON, GRAEME (2014)Since the original discovery of the water-splitting activity of silver orthophosphate (Ag3PO4), considerable effort has been devoted to improving its photocatalytic activity and stability through morphology control and the ... -
The electronic structure of the antimony chalcogenide series: Prospects for optoelectronic applications
WATSON, GRAEME; ALLEN, JEREMY (2014)In this study, density functional theory is used to evaluate the electronic structure of the antimony chalcogenide series. Analysis of the electronic density of states and charge density shows that asymmetric density, or ... -
Electronic structures of silver oxides
WATSON, GRAEME; ALLEN, JEREMY; SCANLON, DAVID (2011)The oxides of silver have a number of important technological applications, including use in battery technology, catalysis, and in the treatment of dermatological conditions. However, only the Ag2O phase has been well ... -
Energy-band alignment of II-VI/Zn3P2 heterojunctions from x-ray photoemission spectroscopy
WATSON, GRAEME (2013)The energy-band alignments for zb-ZnSe(001)/ a -Zn 3 P 2 (001), w-CdS(0001)/ a -Zn 3 P 2 (001), and w-ZnO(0001)/ a -Zn 3 P 2 (001) heterojunctions have been determined using high-resolution x-ray photoelectron ... -
GGA+U description of lithium intercalation into anatase TiO2
WATSON, GRAEME (2010)We have used density-functional theory [generalized gradient approximation (GGA)] to study lithium intercalation at low concentration into anatase TiO 2. To describe the defect states produced by Li doping a Hubbard " +U ... -
Hole localization in Al doped silica: A DFT+U description
WATSON, GRAEME (2006)Despite density functional theory (DFT) being the most widely used ab initio approach for studying the properties of oxide materials, the modeling of localized hole states in doped or defective oxides can be a challenge. ... -
The importance of polarizability in the modeling of ionic diffusion in ceria
WATSON, GRAEME (2017) -
Interface stoichiometry control to improve device voltage and modify band alignment in ZnO/Cu2O heterojunction solar cells
WATSON, GRAEME (2014)The interface stoichiometry of cuprous oxide (Cu2O) prepared by thermal oxidation was controlled by adjusting the O2 and Zn partial pressures during ZnO sputter deposition and measured by high-resolution X-ray photoelectron ... -
Modeling the polaronic nature of p-type defects in Cu2O: The failure of GGA and GGA plus U
WATSON, GRAEME; SCANLON, DAVID (2009)Cuprous oxide (Cu2O) is an abundant, low cost, nontoxic semiconductor material with a direct band gap of 2.17 eV.1 Interest in this prototypical p-type conducting oxide is due to its potential use for photovoltaic powercell ...