KEY RESEARCH INTERESTS

• Physical and electronic structure of complex oxides - surfaces and interfaces : e.g. perovskites (LaAlO₃, SrTiO₃, LaMnO₃)
• Electronic structure of oxide semiconductors: e.g. TCO's (CdO, ZnO and In₂O₃)
• Surface and interface electronic structure of III-nitride semiconductor materials (e.g. InN, InGaN & InAlN)
• In-situ studies of epitaxial growth of binary and complex oxides by pulsed laser deposition (PLD)
• Ion-surface interactions for surface and interface structure determination (CAICISS & MEIS of nitrides, oxides and metal alloys).

LATEST NEWS

A fully funded 3.5 year PhD studentship is available from September 2012. The project entitled "Oxide Heterostructures: Next Generation Sustainable Electronic Materials" will use teh new pulsed laser MBE facility for growing novel oxide materiuals and artiuficial heterostructures and is a collaboration with Prof Pam Thomas' group. The aim is to investigate the surface and interface properties using in-situ X-ray photoelectron spectroscopy (XPS), scanning tunnelling microscopy (STM) and atomic force microscopy (AFM), and ex-situ using X-ray diffraction (XRD) and electron microscopy (TEM). Full details of the project can be downloaded here .

CFM GROUP NEWS

CFM was appointed Director of the Birmingham and Warwick Science Cities Research Alliance (SCRA) with effect from December 2011.

The group recently benefitted from £1.5M of capital investment funding for new equipment from Advantage West Midlands (AWM) and teh European Research and Development Fund (ERDF), under the Science Cities initiative, and we have purchased two completely new UHV growth and surface analysis systems. The first is a combined pulsed laser deposition (PLD) facility with in-situ high pressure RHEED, XPS and variable temperature STM/AFM capability, and the second is an ultra-high resolution electron spectroscopy system combining monochromatic X-ray photoelectron spectroscopy (XPS) with state-of-the-art monochromatic UV angle-resolved photoelectron spectroscopy (ARPES).

We published the first comprehensive book on InN and its related alloys InGaN and InAlN, since it was accepted that the band-gap of InN is 0.65 eV rather than the previously accepted value of 1.9 eV. "InN and Related Alloys", CRC Press, Taylor & Francis (ISBN: 978-1-4200-7809-1).

New coaxial impact collision ion scattering spectroscopy (CAICISS) website launched www.caiciss.co.uk

I was recently interviewed to discuss the application of nitride semiconductor materials and their potential impact as high efficiency solar cells. This interview is now a podcast and can be downloaded from http://www2.warwick.ac.uk/newsandevents/audio/?podcastItem=indiumnitride.mp3

FURTHER PARTICULARS

My research group uses electron spectroscopy (high resolution XPS and angle-resolved UV photoelectron spectroscopy (ARPES), along with low energy ion scattering (coaxial impact collision ion scattering spectroscopy - CAICISS) to probe the near-surface structure and electronic properties of semiconducting materials. We also have a range of optical spectroscopies, including absorption, FTIR, UV-vis and Raman spectroscopy. We have also developed semi-classical dielectric theory and charge profile calculations to analyse data from these materials.

Since 2004 we have established a world-leading resreach programme to investigate the surface and interface properties of indium nitride (InN) and obtained the first direct evidence of electron accumulation at an InN(0001) surface grown by molecular beam epitaxy (MBE). In addition we have shown using angle-resolved photoemission (ARPES) that these surface electrons exist in quantized sub-bands. Also when InN is combined with GaN it is now possible to tune the band-gap of InGaN alloys to reproduce any frequency of light emission across the entire visible spectrum - the first time this has been achievable in a single materials system.

More recently we have been investigating the properties of transparent (semi-)conducting oxide materials (TCO's such as CdO, ZnO, SnO₂ and In₂O₃) - all of which exhibit a range of interesting electronic structure and properties. This work is possible because of the improvement in the epitaxial growth quality of these oxide materials as single crystal thin films. We are currently expanding the area of research with the addition of a new combined pulsed laser deposition (PLD) facility equipped with in-situ high pressure RHEED, XPS and STM/AFM capability for investigating both binary and complex perovskite oxide surfaces and interfaces grown in-situ.

The overall aim of the research is to further the understanding of the physical, electronic and transport properties of epitaxially grown semiconducting materials for applications in a broad range of novel device structures.

COLLABORATIONS

We have a number of fruitful interdisciplinary collaborations with groups in the UK and internationally. In the UK we have strong links with Oxford (Prof. Russ Egdell) on the growth and characterisation of oxide materials grown by MBE. Internationally we collaborate with research groups growing both III-nitrides and oxides by MBE and MOVPE, including the groups at: Ritsumiekin University, Japan (Prof. Y. Nanishi), University of Buffalo, USA (Prof. S.M. Durbin), UC Santa Barbara, USA (Prof. J.S. Speck), CNRS, Valbonne, France (Dr. J. Zuniga-Perez), and University of Valencia, Spain (Prof. V. Munoz-Sanjose). All these groups have supplied either InN, InAlN and InGaN samples, or CdO, In₂O₃ and ZnO samples for electron and optical spectroscopy experiments based at Warwick. We also collaborate with the University of Aarhus, Denmark (Prof. Phillip Hofmann) to use the ASTRID synchrotron radiation source for UV photoemission studies, and with the theoretical physics groups at the Friedrich Schiller University, Jena, Germany (Prof. F. Bechstedt) and UC Santa Barbara, USA (Prof. C.G. van der Walle), who perform band structure calculations using density functional theory.

Overall I have published papers on many aspects of semiconductor surfaces, interface formation and epitaxial growth as the author and co-author of more than 225 publications in international refereed journals which have attracted over 4000 citations (h-index 35) and I have published 3 book chapters. I have also delivered over 60 invited talks at international meetings and 70 invited seminars and colloquia. To see the full list of publications, research grants and conference presentations use the links from this page.

SELECTED PUBLICATIONS

• Surface Structure of GaP(110): Ion Scattering and Density Functional Theory Study, L. Fishwick, M. Walker, M.K. Bradley, D.P. Woodruff and C.F. McConville, Phys. Rev. B, 85 (2012) 045322.
• Electron Mobility in CdO Films, S. Vasheghani Farahani, T. D. Veal, P. D. C. King, J. Zuñiga-Pérez, V. Muñoz-Sanjosé and C.F. McConville, J. Appl. Phys. 109 (2011) 073712.
• Polarity Effects in the Soft-X-ray Photoemission of ZnO, M. Allen, D. Zemlyanovy, G.I.N. Waterhouse, J.B. Metson, T.D. Veal, C.F. McConville and S.M. Durbin, Appl. Phys. Lett. 98 (2011) 101906.
• Surface Band-Gap Narrowing in Quantized Electron Accumulation Layers, P.D.C. King, T.D. Veal, C.F. McConville, A. Schleife, J. Zuňiga-Pérez, V. Muňoz-Sanjosé, M. Hopkinson, E.D.L. Rienks, M. Fuglsang and Ph. Hofmann, Phys. Rev. Lett. 104 (2010) 256803.
• Bulk Transport Masurements in ZnO: The Effect of Surface Electron Layers, M. Allen, C.H. Swartz, T.H. Meyers, T.D. Veal, C.F. McConville and S.M. Durbin, Phys. Rev. B 81 (2010) 075211.
• Surface, Bulk and Interface Electronic Properties of Non-Polar InN, W.M. Linhart, T.D. Veal, P.D.C. King, G. Koblmüller, C.S. Gallinat, J.S. Speck and C.F. McConville, Appl. Phys. Lett. 97 (2010) 112103.
• Valence Band Electronic Structure of CdO, ZnO and MgO from X-ray Photoemission Spectroscopy and Quasi-Particle Density Functional Theory Calculations, P.D.C. King, T.D. Veal, A. Schleife, J. Zuňiga-Pérez, B. Martel, P.H. Jefferson, F. Fuchs, V. Muňoz-Sanjosé, F. Bechstedt and C.F. McConville, Phys. Rev. B, 79 (2009) 205205.
• Unification of the Electrical Behaviour of Defects, Impurities and Surface States in Semiconductors: Virtual Gap States in CdO, P.D.C. King, T.D. Veal, P.H. Jefferson, J. Zuňiga-Pérez, V. Muňoz-Sanjosé and C.F. McConville, Phys. Rev. B, 79 (2009) 035203
• Surface Electron Accumulation and the Charge Neutrality Level in In₂O_3, P.D.C. King, T.D. Veal, D.J. Payne, A. Bourlange, R.G. Egdell and C.F. McConville, Phys. Rev. Lett. 101 (2008) 116808.
• Unintentional Conductivity of Indium Nitride: Transport Modelling and Microscopic Origins, P.D.C. King, T.D. Veal and C.F. McConville, J. Phys.: Cond. Matt. 21 (2009) 174.
• Valence Band Offset of the ZnO/AlN Heterojunction Determined by X-ray Photoelectron Spectroscopy, T.D. Veal, P.D.C. King, S.A. Hatfield, , L.R. Bailey, C.F. McConville, B. Martel, J.C. Moreno, E. Frayssinet, F. Semond and J. Zuňiga-Pérez, Appl. Phys. Lett. 93 (2008) 202108.
• Surface Electronic Properties of Undoped InAlN Alloys, P.D.C. King, T.D. Veal, A. Adikimenakis, Hai Lu, L.R. Bailey, E. Ilopoulos, A. Georgakilas, W. J. Schaff and C.F. McConville, Appl. Phys. Lett. 92 (2008) 172105.
• Band-gap and Effective Mass Determination of Epitaxial CdO, P.H. Jefferson , T.D. Veal, S.A. Hatfield, P.D.C. King, C.F. McConville, J. Zuňiga-Pérez and V. Muňoz-Sanjosé, Appl. Phys. Lett. 92 (2008) 022101.
• Coupled Poisson-Schrödinger Solutions for Quantized Electron Accumulation Layers: Band Bending, Charge Profile and Subbands at InN Surfaces, P.D.C. King, T.D. Veal and C.F. McConville, Phys. Rev. B 77 (2008) 125305.
• Determination of the Branch Point Energy of InN: Chemical Trends in Common Cation and Common-Anion Semiconductors, P.D.C. King, T.D. Veal, P.H. Jefferson, S.A. Hatfield, L.F.J. Piper, J. Furthmuller, F. Bechstedt, W. J. Schaff and C.F. McConville, Phys. Rev. B 77 (2008) 045316.
• Indium Adlayers on c-Plane InN Surfaces: A Polarity Dependent Study by X-Ray Photoelectron Spectroscopy, T.D. Veal, P.D.C. King, P.H. Jefferson, C.F. McConville, Hai Lu, W.J. Schaff, P.A. Anderson, S.M. Durbin, D. Muto, H. Naoi and Y. Nanishi, Phys. Rev. B 76 (2007) 075313.
• Universality of Electron Accumulation at Wurtzite, c- and a-Plane and zinc-blende InN Surfaces, P.D.C. King, T.D. Veal, P.H. Jefferson, L.F.J. Piper, C.F. McConville, P. Schley, R. Goldhahn, J. Schormann, D.J. As, K. Lischka, D. Muto, H. Naoi, Y. Nanishi, Hai Lu and W. J. Schaff, Applied Physics Letters 91 (2007) 092101.
• Variation of Band Bending at the Surface of Mg-doped InGaN: Evidence of p-type Conductivity across the Composition Range, P.D.C. King, T.D. Veal, P.H. Jefferson, C.F. McConville, Hai Lu and W.J. Schaff, Phys. Rev. B 75 (2007) 115312.
• Quantized Electron Accumulation States in Indium Nitride studies by Angle-Resolved Photoemission Spectrocopy, L. Colakerol, et al. Phys. Rev. Lett. 97 (2006) 237601.
• Intrinsic Electron Accumulation at clean InN Surfaces, I. Mahboob, T.D. Veal, C.F. McConville, H. Lu and W.J. Schaff, Phys. Rev. Lett. 92 (2004) 036804.
• Negative Band Gaps in Dilute InNSb Alloys, T.D. Veal, I. Mahboob and C.F. McConville, Phys. Rev. Lett. 92 (2004) 136801.

Write to:

Professor C.F. McConville

Department of Physics

University of Warwick

Coventry CV4 7AL UK.

Contact Details:

Office: P429

Telephone:

+44 (0)24 7652 4236
(Direct line)

+44 (0)24 7652 3965

(PA - Ms. Mona Shorehdeli)

Fax:

+44 (0)24 7615 0897 (Departmental)

E-Mail:

C.F.McConville@warwick.ac.uk