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Feliciano Giustino

Professor Feliciano Giustino
Professor of Materials

Department of Materials
University of Oxford
16 Parks Road
Oxford OX1 3PH
UK

Tel: +44 1865 612790
Tel: +44 1865 612790 (Room 271.40.27)
Tel: +44 1865 273777 (reception)
Fax: +44 1865 273789 (general fax)

Personal Homepage
Materials Modelling Laboratory

Summary of Interests

My main research interest in the development and application of atomistic simulation methods for real materials. My strategy is to combine the predictive capability of the quantum theory of real materials with the power of high-performance computing, in order to investigate the structural, electronic, and optical properties of third-generation solar cells and superconductors. My research group is currently active in the following areas:

  • Photovoltaics
    • Solid-state dye-sensitised solar cells
    • Hybrid organic/inorganic solar cells
  • Superconductors
    • Graphane
    • Diamond
    • Iron pnictides
    • Cuprates
  • Electronic structure methods
    • Electron-phonon interaction
    • Many-body perturbation theory

Research Publications

Savini, G., Ferrari, A. C., Giustino, F. (2010) 'First-principles prediction of doped graphane as a high-temperature electron-phonon superconductor' Physical Review Letters 105 037002.

Schaffry, M., Filidou, V., Karlen, S. D., Gauger, E. M., Benjamin, S. C., Anderson, H. L., Ardavan, A., Briggs, G. A. D., Maeda, K., Henbest, K. B., Giustino, F., Morton, J. J. L., Lovett, B. W. (2010) 'Entangling remote nuclear spins linked by a chromophore' Physical Review Letters 104 200501.

Giustino, F., Cohen, M. L., Louie, S. G. (2010) 'GW method with the self-consistent Sternheimer equation' Physical Review B 81 115105.

Park, C.-H., Giustino, F., Spataru, C. D., Cohen, M. L., Louie, S. G. (2009) 'Angle-resolved photoemission spectra of graphene from first-principles calculations' Nano Letters 9 4234.

Noffsinger, J., Giustino, F., Louie, S.G. and Cohen, M.L. (2009). 'Role of fluorine in the iron pnictides: phonon softening and effective hole doping' Physical Review Letters 102 147003.

Noffsinger, J., Giustino, F., Louie, S.G. and Cohen, M.L. (2009). 'Origin of Superconductivity in boron-doped silicon carbide from first principles' Physical Review B 79 104511.

Park, C.-H., Giustino, F., Spataru, C.D., Cohen, M.L. and Louie, S.G. (2009). 'First-principles study of electron linewidths in graphene' Physical Review Letters 102 076803.

There is a more complete list of publications on my Personal Homepage.

 

Projects Available

Atomic-scale design of perovskites for high-performance photovoltaics
Prof F Giustino

In the past five years perovskite solar cells have emerged as a disruptive solar technology. Last year the solar-to-electricity power conversion efficiency of perovskite solar cells reached the record value of 22%, marking the fastest efficiency rise of all time across existing photovoltaic technologies. Key remaining challenges in this research area are to increase the stability of the active materials, and to develop ever more efficient light absorbers and electron/hole transporters.

In our group we have been working on the atomic-scale computational design of new photovoltaics perovskites, using advanced electronic structure techniques based on density-functional theory and many-body perturbation theory. Recent successes include the prediction and subsequent experimental synthesis of the double perovskites Cs2BiAgBr6, Cs2BiAgCl6, and Cs2InAgCl6 [1,2,3]. Our computational discoveries led to the filing of two patent applications. Please see group webpage for further information, recent publications, and research highlights: http://giustino.materials.ox.ac.uk.

In this DPhil project we want to broaden the scope of our investigation towards new materials families, including chalcogenide perovskites, antiperovskites, and layered perovskites. We will combine medium- to high-throughput combinatorial design techniques with advanced electronic structure methods to predict compound stability, electronic, optical, and transport properties. For the most promising materials candidates our collaborators in the Department of Physics (Prof. Snaith's group) will attempt the experimental synthesis and materials characterisation.

The prospective student is expected to have a strong background in Solid State Physics and Quantum Mechanics, aptitude for mathematical models, and knowledge of at least one major programming or scripting language. Previous experience with density-functional theory calculations and familiarity with supercomputing clusters is desirable but not essential, as appropriate training will be provided as needed.

[1] G. Volonakis, A. A. Haghighirad, R. L. Milot, W. H. Sio, M. R. Filip, B. Wenger, M. B. Johnston, L. M. Herz, H. J. Snaith, and F. Giustino, Cs2InAgCl6: A New Lead-Free Halide Double Perovskite with Direct Band Gap, J. Phys. Chem. Lett., 8, 772 (2017).

[2] M. R. Filip, S. Hillman, A. A. Haghighirad, H. J. Snaith, and F. Giustino, Band gaps of the lead-free halide double perovskites Cs2BiAgCl6 and Cs2BiAgBr6 from theory and experiment, J. Phys. Chem. Lett. 7, 2579 (2016).

[3] G. Volonakis, M. R.Filip, A. A. Haghighirad, N. Sakai, B. Wenger, H. J. Snaith, and F. Giustino, Lead-Free Halide Double Perovskites via Heterovalent Substitution of Noble Metals, J. Phys. Chem. Lett. 7, 1254 (2016).

Also see homepages: Feliciano Giustino

Quantum theory and predictive computational modelling of carrier transport in two-dimensional materials
Prof F Giustino

One of the fundamental properties of semiconductors is their ability to sustain an electric current upon the application of an external electric field. The proportionality coefficient between the drift velocity of charge carriers and the applied field is called the carrier mobility, and is a key design parameter in every opto-electronic device, from transistors to light-emitting diodes, lasers, photo-detectors, and solar cells. For example the mobility sets the maximum theoretical switching speed of CMOS transistors, and ultimately tells us how fast a CPU can go.

Understanding mobilities at the atomic scale within the framework of Quantum Mechanics is challenging, because calculating this parameters requires a detailed knowledge of the electronic and vibrational properties of solids [1]. Very recently it has become possible to calculate carrier mobilities entirely ab initio, that is starting essentially from the Schrödinger equation, and without using any empirical parameters. In our group we have developed a cutting-edge computer code, EPW (epw.org.uk) that can now calculate carrier mobilities from first principles [2]. This code is distributed with the Quantum Espresso materials simulation suite (www.quantum-espresso.org).

In this DPhil project we are interested in applying these recent developments in algorithms and software to investigate electron and hole mobilities in two-dimensional materials. Target compounds include transition-metal dichalcogenide monolayers, silicene, phosphorene, and their heterostructures. The aim of the project is to establish the predictive power of our methods via direct comparison to experiments, and to design artificial heterostructures with superior electrical transport properties. Our group is the Oxford partner of the Graphene Flagship consortium, and close interactions with leading experimental groups working on two-dimensional materials are anticipated.

The prospective student is expected to have a strong background in Solid State Physics and Quantum Mechanics, aptitude for mathematical models, and knowledge of at least one major programming or scripting language. Previous experience with density-functional theory calculations and familiarity with supercomputing clusters is desirable but not essential, as appropriate training will be provided as needed. 

[1] F. Giustino, Electron-phonon interactions from first principles, Rev. Mod. Phys. 89, 015003 (2017).

[2] S. Poncé, E.R. Margine, C. Verdi and F. Giustino, EPW: Electron–phonon coupling, transport and superconducting properties using maximally localized Wannier functions, Comput. Phys. Commun. 209, 116 (2016).

 

Also see homepages: Feliciano Giustino

Predictive first-principles calculations of electronic and optical properties of semiconductors at finite temperature
Prof F Giustino

Density functional theory (DFT) is widely recognised as an enabling tool in modern materials modelling and design. DFT and its improvements allow us to calculate the properties of materials at the atomic scale with predictive accuracy, starting from the first principles of Quantum Mechanics. These calculations are referred to as “ab initio” because they do not require any empirical parameters, such as measured materials properties, and rely exclusively on universal physical constants, for example the electron mass and charge, the Planck constant, and so on.

Despite the enormous success of DFT in materials science, the vast majority of current DFT calculations of the electronic and optical properties of crystals are performed by describing the ionic nuclei as classical point charges, immobile in their equilibrium crystallographic sites. This approximation neglects two important effects, namely that at finite temperature the ions vibrate around their equilibrium sites, and that even at zero temperature there is a residual motion arising from so-called quantum zero-point fluctuations. Several research groups are currently trying to overcome this important limitation of standard DFT calculations.

In our group we recently discovered a powerful new method to incorporate temperature effects and zero-point quantum fluctuations in DFT calculations of electronic band structures and optical properties [1]. Using this new technique we succeeded to calculate temperature-dependent optical absorption spectra and band structures of common semiconductors (e.g. silicon and gallium arsenide), and we obtained a remarkable agreement with experiments. This technique is still under development, and much work needs to be done in order to understand its full potential and its range of applicability.

In this DPhil project we will explore in greater detail the formal properties of this new methodology, and we will explore its applicability to a number of optical properties, for example two-photon optical absorption spectra, photoluminescence spectra, and phonon-assisted Auger spectra. Target materials will be standard semiconductors for the optoelectronic industry, as well as novel solar cell materials such as halide perovskites, and two-dimensional semiconductors such as transition-metal dichalcogenides.

The prospective student is expected to have a strong background in Solid State Physics and Quantum Mechanics, aptitude for mathematical models, and knowledge of at least one major programming or scripting language. Previous experience with density-functional theory calculations and familiarity with supercomputing clusters is desirable but not essential, as appropriate training will be provided as needed.

[1] M. Zacharias and F. Giustino, One-shot calculation of temperature-dependent optical spectra and phonon-induced band-gap renormalization, Phys. Rev. B 94, 075125 (2016).

[2] M. Zacharias, C. E. Patrick, and F. Giustino, Stochastic Approach to Phonon-Assisted Optical Absorption, Phys. Rev. Lett. 115, 177401 (2015).

[3] C. E. Patrick and F. Giustino, Quantum nuclear dynamics in the photophysics of diamondoids, Nat. Commun. 4, 2006 (2013)

Also see homepages: Feliciano Giustino

Also see a full listing of New projects available within the Department of Materials.