Publications for Pooja Goddard
Journal ArticlesZhou, Y, Srinivasan, P, Körmann, F, Grabowski, B, Smith, R, Goddard, P, Duff, AI (2022) Thermodynamics up to the melting point in a TaVCrW high entropy alloy: Systematic ab initio study aided by machine learning potentials, Physical Review B, 105(21), 214302, ISSN: 2469-9950. DOI: 10.1103/PhysRevB.105.214302. Zhou, Y, Srinivasan, P, Körmann, F, Grabowski, B, Smith, R, Goddard, P, Duff, AI (2022) Thermodynamics up to the melting point in a TaVCrW high entropy alloy: Systematic study aided by machine learning potentials, Physical Review B, 105(21), 214302, ISSN: 2469-9950. DOI: 10.1103/physrevb.105.214302. Tan, L, Ali, K, Ghosh, PS, Arya, A, Zhou, Y, Smith, R, Goddard, P, Patel, D, Shahmir, H, Gandy, A (2022) Design principles of low-activation high entropy alloys, Journal of Alloys and Compounds, 907, 164526, ISSN: 0925-8388. DOI: 10.1016/j.jallcom.2022.164526. Hatton, P, Watts, MJ, Abbas, A, Walls, M, Smith, R, Goddard, P (2022) Author correction: Chlorine activated stacking fault removal mechanism in thin film CdTe solar cells: the missing piece, Nature Communications, 13, 404, DOI: 10.1038/s41467-022-28059-4. Dong, B, Haworth, AR, Yeandel, SR, Stockham, MP, James, MS, Xiu, J, Wang, D, Goddard, P, Johnston, KE, Slater, PR (2022) Halogenation of Li7La3Zr2O12 solid electrolytes: a combined solid-state NMR, computational and electrochemical study, Journal of Materials Chemistry A, 10(20), pp.11172-11185, ISSN: 2050-7488. DOI: 10.1039/d1ta07309e. Kimber, P, Goddard, P, Wright, I, Plasser, F (2021) The role of excited-state character, structural relaxation, and symmetry breaking in enabling delayed fluorescence activity in push-pull chromophores, Physical Chemistry Chemical Physics, 23(46), pp.26135-26150, ISSN: 1463-9076. DOI: 10.1039/d1cp03792g. Hatton, P, Watts, M, Abbas, A, Walls, M, Smith, R, Goddard, P (2021) Chlorine activated stacking fault removal mechanism in thin film CdTe solar cells: the missing piece, Nature Communications, 12(1), 4938, DOI: 10.1038/s41467-021-25063-y. Neale, AR, Sharpe, R, Yeandel, SR, Yen, CH, Luzyanin, KV, Goddard, P, Petrucco, EA, Hardwick, LJ (2021) Design Parameters for Ionic Liquid–Molecular Solvent Blend Electrolytes to Enable Stable Li Metal Cycling Within Li–O₂ Batteries, Advanced Functional Materials, ISSN: 1616-301X. DOI: 10.1002/adfm.202010627. Hunnisett, L, Kelly, PF, Bleay, S, Plasser, F, King, R, McMurchie, B, Goddard, P (2021) Mechanistic insight into the fluorescence activity of forensic fingerprinting reagents, The Journal of Chemical Physics, 154(12), 124313, ISSN: 0021-9606. DOI: 10.1063/5.0040555. Watts, MJ, Hatton, P, Smith, R, Fiducia, T, Abbas, A, Greenhalgh, R, Walls, M, Goddard, P (2021) Chlorine passivation of grain boundaries in cadmium telluride solar cells, PHYSICAL REVIEW MATERIALS, 5(3), ARTN 035403, ISSN: 2475-9953. DOI: 10.1103/PhysRevMaterials.5.035403. Amores, M, El-Shinawi, H, McClelland, I, Yeandel, SR, Baker, PJ, Smith, RI, Playford, HY, Goddard, P, Corr, SA, Cussen, EJ (2020) Li1.5La1.5MO6 (M = W6+, Te6+) as a new series of lithium-rich double perovskites for all-solid-state lithium-ion batteries, Nature Communications, 11(1), 6392, ISSN: 2041-1723. DOI: 10.1038/s41467-020-19815-5. Ford, LJ, Slater, PR, Christie, J, Goddard, P (2020) Carbon dioxide and water incorporation mechanisms in SrFeO3−δ phases: a computational study, Physical Chemistry Chemical Physics, ISSN: 1463-9076. DOI: 10.1039/d0cp03537h. Hatton, P, Abbas, A, Kaminski, P, Yilmaz, S, Watts, M, Walls, M, Goddard, P, Smith, R (2020) Inert gas bubble formation in magnetron sputtered thin-film CdTe solar cells, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 476(2239), 20200056, ISSN: 1364-5021. DOI: 10.1098/rspa.2020.0056. Hatton, P, Abbas, A, Kaminski, P, Yilmaz, S, Watts, M, Walls, M, Goddard, P, Smith, R (2020) Inert gas bubble formation in magnetron sputtered thin-film CdTe solar cells, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 476(2239), 20200056, ISSN: 1364-5021. DOI: 10.1098/rspa.2020.0056. Case, D, McSloy, AJ, Sharpe, R, Yeandel, SR, Bartlett, T, Cookson, J, Dashjav, E, Tietz, F, Kumar, CMN, Goddard, P (2020) Structure and ion transport of lithium-rich Li1+xAlxTi2−x(PO4)3 with 0.3, Solid State Ionics, 346, ISSN: 0167-2738. DOI: 10.1016/j.ssi.2019.115192. Dong, B, Yeandel, SR, Goddard, P, Slater, PR (2020) Combined Experimental and Computational Study of Ce-Doped La3Zr2Li7O12 Garnet Solid-State Electrolyte, Chemistry of Materials, 32(1), pp.215-223, ISSN: 0897-4756. DOI: 10.1021/acs.chemmater.9b03526. Watts, M, Fiducia, T, Sanyal, B, Smith, R, Walls, M, Goddard, P (Accepted for publication) Enhancement of photovoltaic efficiency in CdSexTe1−x (where 0≤x≤1): Insights from density functional theory, Journal of Physics: Condensed Matter, ISSN: 0953-8984. DOI: 10.1088/1361-648x/ab5bba. Koketsu, T, Ma, J, Morgan, BJ, Body, M, Legein, C, Goddard, P, Borkiewicz, OJ, Strasser, P, Dambournet, D (Accepted for publication) Exploiting cationic vacancies for increased energy densities in dual-ion batteries, Energy Storage Materials, ISSN: 2405-8297. DOI: 10.1016/j.ensm.2019.10.019. Hatton, P, Goddard, P, Smith, R, Abbas, A, Potamialis, C, Greenhalgh, R, Walls, M (2019) Inert gas cluster formation in sputter-deposited thin film CdTe solar cells, Thin Solid Films, 692, 137614, ISSN: 0040-6090. DOI: 10.1016/j.tsf.2019.137614. Edge, J, Cooper, SJ, Aguadero, A, George, C, Titirici, M, Goddard, P (2019) UK Research on Materials for Electrochemical Devices, JOHNSON MATTHEY TECHNOLOGY REVIEW, 63(4), pp.255-260, ISSN: 2056-5135. DOI: 10.1595/205651319X15635449482962. Yeandel, S, Scanlon, DO, Goddard, P (2019) Enhanced Li-ion dynamics in trivalently doped Lithium Phosphidosilicate Li2SiP2: A candidate material as a solid li electrolyte, Journal of Materials Chemistry A, 7(8), pp.3953-3961, ISSN: 2050-7488. DOI: 10.1039/c8ta10788b. Yeandel, S, Chapman, BJ, Slater, PR, Goddard, P (2018) Structure and lithium-ion dynamics in fluoride-doped cubic Li7La3Zr2O12 (LLZO) garnet for Li solid-state battery applications, Journal of Physical Chemistry C, ISSN: 1932-7447. DOI: 10.1021/acs.jpcc.8b07704. McSloy, AJ, Trussov, I, Jarvis, A, Cooke, DJ, Slater, PR, Goddard, P (2018) Mechanism of carbon dioxide and water incorporation in Ba2TiO4: A joint computational and experimental study, Journal of Physical Chemistry C, 122(2), pp.1061-1069, ISSN: 1932-7447. DOI: 10.1021/acs.jpcc.7b10330. Azough, F, Jackson, SS, Ekren, D, Freer, R, Molinari, M, Yeandel, S, Goddard, P, Parker, SC, Maldonado, DH, Kepaptsoglou, DM, Ramasse, QM (2017) Concurrent La and A-site vacancy doping modulates the thermoelectric response of SrTiO3: experimental and computational evidence, ACS Applied Materials and Interfaces, ISSN: 1944-8244. DOI: 10.1021/acsami.7b14231. McSloy, A, Kelly, P, Slater, PR, Goddard, P (2016) A computational study of doped olivine structured Cd2GeO4: local defect trapping of interstitial oxide ions, Physical Chemistry Chemical Physics, ISSN: 1463-9084. DOI: 10.1039/C6CP05436F. Andreev, YG, Panchmatia, PM, Liu, Z, Parker, SC, Islam, MS, Bruce, PG (2014) The Shape of TiO₂-B Nanoparticles, Journal of the American Chemical Society, 136(17), pp.6306-6312, ISSN: 0002-7863. DOI: 10.1021/ja412387c. Panchmatia, PM, Armstrong, AR, Bruce, PG, Islam, MS (2014) Lithium-ion diffusion mechanisms in the battery anode material Li1+xV1−xO2, Phys. Chem. Chem. Phys, 16(39), pp.21114-21118, ISSN: 1463-9076. DOI: 10.1039/c4cp01640h. Šupuk, E, Ghori, MU, Asare-Addo, K, Laity, PR, Panchmatia, PM, Conway, BR (2013) The influence of salt formation on electrostatic and compression properties of flurbiprofen salts, International Journal of Pharmaceutics, 458(1), pp.118-127, ISSN: 0378-5173. DOI: 10.1016/j.ijpharm.2013.10.004. Bhandary, S, Brena, B, Panchmatia, PM, Brumboiu, I, Bernien, M, Weis, C, Krumme, B, Etz, C, Kuch, W, Wende, H, Eriksson, O, Sanyal, B (2013) Manipulation of spin state of iron porphyrin by chemisorption on magnetic substrates, Physical Review B, 88(2), 024401, ISSN: 1098-0121. DOI: 10.1103/physrevb.88.024401. Howard, MA, Clemens, O, Knight, KS, Anderson, PA, Hafiz, S, Panchmatia, PM, Slater, PR (2013) Synthesis, conductivity and structural aspects of Nd3Zr2Li7−3xAlxO12, Journal of Materials Chemistry A, 1(44), pp.14013-14013, ISSN: 2050-7488. DOI: 10.1039/c3ta13252h. Dufton, JTR, Walsh, A, Panchmatia, PM, Peter, LM, Colombara, D, Islam, MS (2012) Structural and electronic properties of CuSbS2 and CuBiS2: potential absorber materials for thin-film solar cells, Physical Chemistry Chemical Physics, 14(20), pp.7229-7229, ISSN: 1463-9076. DOI: 10.1039/c2cp40916j. Panchmatia, PM, Orera, A, Rees, GJ, Smith, ME, Hanna, JV, Slater, PR, Islam, MS (2011) Oxygen Defects and Novel Transport Mechanisms in Apatite Ionic Conductors: Combined 17O NMR and Modeling Studies, Angewandte Chemie International Edition, 50(40), pp.9328-9333, ISSN: 1433-7851. DOI: 10.1002/anie.201102064. Armstrong, AR, Lyness, C, Panchmatia, PM, Islam, MS, Bruce, PG (2011) The lithium intercalation process in the low-voltage lithium battery anode Li1+xV1−xO2, Nature Materials, 10(3), pp.223-229, ISSN: 1476-1122. DOI: 10.1038/nmat2967. Malavasi, L, Orera, A, Slater, PR, Panchmatia, PM, Islam, MS, Siewenie, J (2011) Local structure investigation of oxide ion and proton defects in Ge-apatites by pair distribution function analysis, Chem. Commun, 47(1), pp.250-252, ISSN: 1359-7345. DOI: 10.1039/c0cc00523a. Panchmatia, PM, Ali, ME, Sanyal, B, Oppeneer, PM (2010) Halide Ligated Iron Porphines: A DFT+U and UB3LYP Study, The Journal of Physical Chemistry A, 114(51), pp.13381-13387, ISSN: 1089-5639. DOI: 10.1021/jp106358m. Panchmatia, PM, Orera, A, Kendrick, E, Hanna, JV, Smith, ME, Slater, PR, Islam, MS (2010) Protonic defects and water incorporation in Si and Ge-based apatite ionic conductors, Journal of Materials Chemistry, 20(14), pp.2766-2766, ISSN: 0959-9428. DOI: 10.1039/b924220a. Oppeneer, PM, Panchmatia, PM, Sanyal, B, Eriksson, O, Ali, ME (2009) Nature of the magnetic interaction between Fe-porphyrin molecules and ferromagnetic surfaces, Progress in Surface Science, 84(1-2), pp.18-29, ISSN: 0079-6816. DOI: 10.1016/j.progsurf.2008.12.001. Bernien, M, Miguel, J, Weis, C, Ali, ME, Kurde, J, Krumme, B, Panchmatia, PM, Sanyal, B, Piantek, M, Srivastava, P, Baberschke, K, Oppeneer, PM, Eriksson, O, Kuch, W, Wende, H (2009) Tailoring the Nature of Magnetic Coupling of Fe-Porphyrin Molecules to Ferromagnetic Substrates, Physical Review Letters, 102(4), 047202, ISSN: 0031-9007. DOI: 10.1103/physrevlett.102.047202. Panchmatia, PM, Sanyal, B, Oppeneer, PM (2008) GGA+U modeling of structural, electronic, and magnetic properties of iron porphyrin-type molecules, Chemical Physics, 343(1), pp.47-60, ISSN: 0301-0104. DOI: 10.1016/j.chemphys.2007.10.030. Wende, H, Bernien, M, Luo, J, Sorg, C, Ponpandian, N, Kurde, J, Miguel, J, Piantek, M, Xu, X, Eckhold, P, Kuch, W, Baberschke, K, Panchmatia, PM, Sanyal, B, Oppeneer, PM, Eriksson, O (2007) Substrate-induced magnetic ordering and switching of iron porphyrin molecules, Nature Materials, 6(7), pp.516-520, ISSN: 1476-1122. DOI: 10.1038/nmat1932. Newman, DM and Panchmatia, P (2003) Nanoscale silver oxide: A rewritable optical recording medium, IEE Proceedings - Science, Measurement and Technology, 150(5), pp.214-217, ISSN: 1350-2344. DOI: 10.1049/ip-smt:20030824.
ConferencesGreenhalgh, R, Hatton, P, Kornienko, V, Abbas, A, Goddard, P, Smith, R, Bowers, J, Walls, M (2021) The origins of void formation in sputtered CdSe. In 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC); 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC), Fort Lauderdale, FL, USA, pp.886-889, ISBN: 9781665419222. DOI: 10.1109/pvsc43889.2021.9519113. Watts, M, Yeandel, S, Smith, R, Walls, M, Goddard, P (2018) Atomistic insights of multiple stacking faults in CdTe thin-film photovoltaics: A DFT study. In 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC), 2018,, Waikoloa Village, HI, USA, pp.3884-3887, ISBN: 9781538685297. DOI: 10.1109/PVSC.2018.8547934. Kendrick, E, Kendrick, J, Orera, A, Panchmatia, P, Islam, MS, Slater, PR (2011) Novel Aspects of the Conduction Mechanisms of Electrolytes Containing Tetrahedral Moieties. In , Fuel Cells, pp.38-43, DOI: 10.1002/fuce.201000044. Orera, A, Baikie, T, Panchmatia, P, White, TJ, Hanna, J, Smith, ME, Islam, MS, Kendrick, E, Slater, PR (2011) Strategies for the Optimisation of the Oxide Ion Conductivities of Apatite-Type Germanates. In , Fuel Cells, pp.10-16, DOI: 10.1002/fuce.201000020. Panchmatia, PM, Sanyal, B, Oppeneer, PM (2007) Ab initio calculations of the electronic structure and magnetism of iron porphyrin-type molecules: A benchmarking study. In , Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), pp.502-509, ISBN: 9783540757542. DOI: 10.1007/978-3-540-75755-9_61.
DatasetsGoddard, P, Smith, R, Walls, M, Abbas, A, Fiducia, T, Watts, M, Hatton, P (2021) Data for the article: Chlorine activated stacking fault removal mechanism in thin film CdTe solar cells: the missing piece, DOI: 10.17028/rd.lboro.14842518.
OtherHatton, P, Watts, M, Abbas, A, Fiducia, T, Walls, J, Smith, R, Goddard, P (2021) Chlorine activated stacking fault removal mechanism in thin film CdTe solar cells: the whole story,
The efficiency of as-deposited CdTe solar cells is typically <5 %. An activation process involving the post-treatment of the CdTe surface with cadmium chloride at approximately 400 deg C improves the absorber microstructure by removing stacking faults, fills the grain boundaries with chlorine and leads to efficiencies of up to ~22 %. Stacking fault removal and improvement in device efficiency are thus correlated but the question of whether this correlation is direct or indirect has to date not been established. Although some types of stacking fault could be hole traps, those most commonly observed are tetrahedral in nature which recent work has shown to be electrically benign. For the first time, in this paper, we not only explain the passivation responsible for this efficiency increase but crucially elucidate the associated stacking fault removal mechanism. Experimental work shows that as chlorine is added to the system, the stacking faults gradually disappear from the absorber layer upwards to the surface with some grains being fault-free in the intermediate state before full saturation. At saturation chlorine decorates all the grain boundaries and so the effect of chlorine on a model system of a tetrahedral stacking fault bounded by two grain boundaries is investigated using density functional theory (DFT). We find that if the stacking faults between the grain boundaries were to be removed without Cl, this would result in an energy increase for the system. Increasing the chlorine concentration in the grain boundaries decreases the energy difference between the faulted and unfaulted system until a cross-over occurs close to the point at which chlorine saturates the grain boundaries. The atomic mechanisms and energy profile for the stacking fault removal is presented. The removal process is via a cascade effect whereby the system energy gradually increases as the fault is sequentially removed until the layers snap into place. The energy barrier for this to occur is easily overcome with the 400 deg C temperature treatment. Density of States (DOS) plots of the chlorine saturated structures show that defect passivation occurs in the highly reconstructed grain boundaries due to both interstitial and substitutional chorine. Chlorine saturation is shown to disconnect the two sides of the grain boundary avoiding electronic defects which arise from the interaction of dangling bonds across this region. It is thus concluded that the cell efficiency increase observed is due to the electronic effects of chlorine in the grain boundaries and that the observed stacking fault removal is a bi-product of the chlorine grain boundary saturation.. DOI: 10.21203/rs.3.rs-333846/v1. Kimber, P, Goddard, P, Wright, I, Plasser, F (Accepted for publication) The role of excited-state character, structural relaxation, and symmetry breaking in enabling delayed fluorescence activity in push-pull chromophores,
Thermally activated delayed fluorescence (TADF) is a current promising route for generating highly efficient light-emitting devices. However, the design process of new chromophores is hampered by the complicated underlying photophysics that requires a number of different pathways to be optimised simultaneously. In this work, four closely related donor-pi-acceptor-pi-donor systems have been investigated, two of which were synthesised previously, with the aim of elucidating their varying effectiveness for TADF. We, first, outline that neither the frontier orbitals nor the singlet-triplet gaps are sufficient in discriminating between the molecules. Subsequently, a detailed analysis of the excited states, performed at a correlated ab initio level, is shown highlighting the presence of a number of closely spaced singlet and triplet states of varying character. Five density functionals are benchmarked against this reference revealing dramatic changes in, both, excited state energies and wavefunctions following variations in the amount of Hartree-Fock exchange included. Excited-state minima are optimised in solution showing the crucial role of structural variations for stabilising locally excited and CT states and of symmetry breaking for producing a strongly emissive S1 state. More generally, this work shows how a detailed analysis of excited-state wavefunctions can provide critical new insight into excited-state electronic structure, helping to reveal the photophysics of existing push-pull chromophores and ultimately guiding the design of new ones.. DOI: 10.33774/chemrxiv-2021-b3jfg.