Descriptors for the nature of electron and hole charge carriers from first-principles calculations data

This presentation summarises the work in this JPCL publication https://pubs.acs.org/doi/abs/10.1021/acs.jpclett.9b03398.

Transcript

1. Descriptors for the nature of electron and hole charge carriers from first- principles calculations data Dan Davies MRS Fall Meeting MT03 5th December 2019 @danwdavies
2. Conductivity of metal oxides Insulating Metallic TiO MgO In2 O3 (Sn-doped) Fe2 O3
3. Conductivity of metal oxides Insulating Metallic TiO MgO In2 O3 (Sn-doped) Fe2 O3
4. Descriptor 1: Carrier effective mass L. D. Whalley, effmass: An effective mass package, Journal of Open Source Software, 2018 Effective mass Mobility n-type Conductivity p-type
5. Descriptor 1: Carrier effective mass Ricci et al., An ab initio electronic transport database for inorganic materials, Sci. Data, 2017 5,548 metal oxides Electrons Holes A. M. Ganose et al., sumo: Command- line tools for plotting and analysis of periodic ab initio calculations, Journal of Open Source Software, 2018  X M  Z R A Z −4 −2 0 2 4 6 8 Energy (eV) O (p) Sn (s) Sn (p) Sn (d) E.g. SnO2
6. Polarons P. A. Cox, Electronic Structure and Chemistry of Solids, 1987 Quasiparticles describing a charge carrier plus surrounding polarization of the lattice
7. Descriptor 2: Polaron binding energy S. Pekar, Local quantum states of electrons in an ideal ion crystal, J. Exp. Theor. Phys., 1946 H. Fröhlich, Electrons in lattice fields, Adv. Phys., 1954
8. Descriptor 2: Polaron binding energy S. Pekar, Local quantum states of electrons in an ideal ion crystal, J. Exp. Theor. Phys., 1946 H. Fröhlich, Electrons in lattice fields, Adv. Phys., 1954
9. Polaron energies from available data Ricci et al., An ab initio electronic transport database for inorganic materials, Sci. Data, 2017 G. Petretto et al., High-throughput density functional perturbation theory phonons for inorganic materials, Sci. Data, 2018 Electrons Holes 214 metal oxides Type I Type II Type III
10. Polaron energies from available data Ricci et al., An ab initio electronic transport database for inorganic materials, Sci. Data, 2017 G. Petretto et al., High-throughput density functional perturbation theory phonons for inorganic materials, Sci. Data, 2018 Electrons Holes n-type materials Similar m* ZnO SnO2 BaSnO3 4 meV 10 meV 11 meV LiRhO2 K2 SrTa2 O7 4.40 4.38 129 meV 730 meV m* Epolaron 214 metal oxides
11. The search for p-type oxides • Hybrid DFT (HSE06) • DFPT (PBE) • BoltzTraP Calculations performed by Chris Savory (UCL) Formula e h e h PtO2 0.04 0.03 0.5 1.5 CuRhO2 0.1 0.5 0.5 2.2 LiAg3 O2 3.5 2.5 18 11 NaNbO2 4.9 2.6 5.9 2.9 Ca4 Bi2 O 3.3 4.8 12 14 YZnAsO 5.9 5.1 17 30 NaAg3 O2 5.2 6.0 14 17 LaZnAsO 3.2 6.0 7.9 19 YZnPO 9.0 6.1 13 19 LiNbO2 24 6.5 36 6.6 Epolaron (meV) Database HSE06
12. The search for p-type oxides Band gap PBE 0.58 eV HSE06 1.36 eV Expt. 1.5 eV PBE 7.1 HSE06 18.8 m* electron hole PBE 0.85 0.58 HSE06 0.55 0.77 Formula e h e h PtO2 0.04 0.03 0.5 1.5 CuRhO2 0.1 0.5 0.5 2.2 LiAg3 O2 3.5 2.5 18 11 NaNbO2 4.9 2.6 5.9 2.9 Ca4 Bi2 O 3.3 4.8 12 14 YZnAsO 5.9 5.1 17 30 NaAg3 O2 5.2 6.0 14 17 LaZnAsO 3.2 6.0 7.9 19 YZnPO 9.0 6.1 13 19 LiNbO2 24 6.5 36 6.6 Epolaron (meV) Database HSE06 Calculations performed by Chris Savory (UCL)
13. Descriptor 3: Charge carrier mobility J. M. Frost, PolaronMobility.jl: Implementation of the Feynman variational polaron model, Journal of Open Source Software, 2018 Limited by optical (Fröhlich) scattering at > 300K • Effective mass • Dielectric constant • Phonon spectrum • Born effective charges (Hybrid) DFT ⍵optic Hellwarth Feynman R. W. Hellwarth et al., Mobility of an electron in a multimode polar lattice, Phys. Rev. B, 1999 R. P. Feynman, Slow electrons in a polar crystal, Phys. Rev., 1955 PolaronMobility.jl solves the Feynman variational solution for a finite temp extension of Fröhlich’s polar Hamiltonian
14. Descriptor 3: Charge carrier mobility J. M. Frost, PolaronMobility.jl: Implementation of the Feynman variational polaron model, Journal of Open Source Software, 2018 Limited by optical (Fröhlich) scattering at > 300K • Effective mass • Dielectric constant • Phonon spectrum • Born effective charges (Hybrid) DFT ⍵optic Hellwarth Feynman R. W. Hellwarth et al., Mobility of an electron in a multimode polar lattice, Phys. Rev. B, 1999 R. P. Feynman, Slow electrons in a polar crystal, Phys. Rev., 1955 PolaronMobility.jl solves the Feynman variational solution for a finite temp extension of Fröhlich’s polar Hamiltonian
15. Direct calculation of charge carrier mobility All 10 candidates have µ > 10 Higher ⍵optic leads to higher µ Several materials reported as p-type conductors in the experimental literature Formula ⍵optic e h PtO2 713 853 175 CuRhO2 590 631 67 LiAg3 O2 429 30 60 NaNbO2 464 48 145 Ca4 Bi2 O 105 31 26 YZnAsO 307 28 11 NaAg3 O2 439 41 29 LaZnAsO 281 67 17 YZnPO 302 45 26 LiNbO2 420 6 88 (cm2V-1s-1)
16. Summary • Modern materials datasets can facilitate rapid screening for effective mass, polaron binding energy and mobility • The polaron energy metric can be used as a descriptor for conductivity • Delocalized Intermediate Localized Type I Type II Type III ChemRxiv: Descriptors for Electron and Hole Charge Carriers in Metal Oxides
17. Acknowledgements • Aron Walsh • Chris Savory (UCL) • David Scanlon (UCL) • Jarvist Frost (Imperial College physics) • Jonathan Skelton (Manchester) • Benjamin Morgan (Bath) Toolbox • https://github.com/wmd-group/smact • http://pymatgen.org/ • https://github.com/jarvist/PolaronMobility.jl • https://github.com/JMSkelton/Phonopy-Spectroscopy • http://www.icams.de/content/research/software-development/boltztrap/
18. Data access Github.com/FaradayInstitution/charge_carriers_data