Group Leader

Contact information: Lawrence Livermore National Laboratory 7000 East Avenue, L-413 Livermore, CA 94550 email:  lordi2@llnl.gov phone:  925-423-2755 Google Scholar profile

Education:

• Ph.D. in Materials Science & Engineering, Stanford University (Hertz Fellow), 2004
• M.S. in Electrical Engineering, Stanford University, 2002
• B.S.E. in Chemical Engineering, Princeton University, 1999
  (minors:  Applied Mathematics, Materials Science)

Research:

My research focuses on the study of the structural, electronic, optical and optoelectronic properties of semiconductors and nanostructures, emphasizing the relationships among defects, electronic structure, and device performance. Surface and interface effects, as well as alloy effects, are also of interest. Theory and computation, using primarily ab initio electronic structure, molecular dynamics, and kinetic Monte Carlo, are the main tools applied to these problems, but experiments are employed as well including optical and X-ray spectroscopy and transmission electron microscopy. A common theme of my research is the study of “real” materials to enable effective materials design.

Current projects span various applications:

• Surface and defect engineering of materials for superconducting, semiconducting, and ion qubits
• Semiconductor and amorphous materials for high-energy radiation detection
• Ultra-wide band gap materials for power electronics
• Interface chemistry in lithium ion batteries
• Materials for high-performance thin-film photovoltaic devices
• Metal alloys and oxides for novel nuclear fuel materials
• Glass doping for tunable optical filters in high-fluence applications

Selected publications:

• V. Lordi and J. Nichol, Advances and opportunities in materials science for scalable quantum computing.  MRS Bulletin 46, 1 (2021).
• C.E. Kim, K.G. Ray, and V. Lordi, Density-functional theory study of the Al/AlO_x/Al tunnel junction .  Journal of Applied Physics 128, 155102 (2020). Invited, Featured Article, Cover Article
• T.A. Pham, M.T. Ong, K.E. Kweon, A. Samanta, V. Lordi, and J.E. Pask, Intercalation of Lithium into Graphite: Insights from First-Principles Simulations.  Journal of Physical Chemistry C 124(40), 21985-21992 (2020).
• J.B. Varley, A. Perron, V. Lordi, D. Wickramaratne, and J.L. Lyons, Prospects for n-type doping of (Al_xGa_1−x)₂O₃ alloys.  Applied Physics Letters 116, 172104 (2020). Fast Track, Editor's Pick
• C.J.K. Richardson, V. Lordi, S. Misra, and J. Shabani, Materials Science for Quantum Information Science and Technology.  MRS Bulletin 45(6), 485 (2020).
• V. Lordi, “Delving into dynamic effects,” Nature Chemistry 12, 225–226 (2020).
• M. Nardone, Y. Patikirige, K.E. Kweon, C. Walkons, T. Magorian Friedlmeier, J.B. Varley, V. Lordi, and S. Bansal, “Quantifying Large Lattice Relaxations in Photovoltaic Devices,” Physical Review Applied 13, 024025 (2020).
• C. Noel, M. Berlin-Udi, C. Matthiesen, J. Yu, Y. Zhou, V. Lordi, and H. Häffner, “Electric-field noise from thermally activated fluctuators in a surface ion trap,” Physical Review A 99, 063427 (2019).
• K.G. Ray, B.M. Rubenstein, W. Gu and V. Lordi, “van der Waals-corrected density functional study of electric field noise heating in ion traps caused by electrode surface adsorbates,” New Journal of Physics 21 053043 (2019.
• X. He, P. Ercius, J.B. Varley, J. Bailey, G. Zapalac, T. Nagle, D. Poplavskyy, N. Mackie, A. Bayman, V. Lordi, and A. Rockett, “The role of oxygen doping on elemental intermixing at the PVD‐CdS/Cu (InGa)Se2 heterojunction ,” Progress in Photovoltaics: research and applications 27 255-263 (2019).
• J. Varley, A. Samanta, and V. Lordi, “Descriptor-Based Approach for the Prediction of Cation Vacancy Formation Energies and Transition Levels,” The Journal of Physical Chemistry Letters 8, 5059 (2017).
• T.A. Pham, K.E. Kweon, A. Samanta, V. Lordi, and J. Pask, “Solvation and Dynamics of Sodium and Potassium in Ethylene Carbonate from Ab Initio Molecular Dynamics Simulations,” The Journal of Physical Chemistry Part C 121, 21913 (2017).
• J.B. Varley, V. Lordi, X. He, and A. Rockett, “Exploring Cd-Zn-O-S alloys for improved buffer layers in thin-film photovoltaics,” Physical Review Materials 1, 025403 (2017).
• M.T. Ong, H. Bhatia, A.G. Gyulassy, E.W. Draeger, V. Pascucci, P.-T. Bremer, V. Lordi, and J.E. Pask, “Complex Ion Dynamics in Carbonate Lithium-Ion Battery Electrolytes,” Journal of Physical Chemistry C 121, 6589 (2017).
• N. Adelstein, D. Lee, J.L. DuBois, and V. Lordi, “Magnetic stability of oxygen defects on the SiO₂ surface,” AIP Advances 7, 025110 (2017).
• J.B. Varley, X. He, A. Rockett, and V. Lordi, “Stability of Cd_1–xZn_xO_yS_1–y Quaternary Alloys Assessed with First-Principles Calculations,” ACS Applied Materials & Interfaces 9, 5673 (2017).
• X. He, T. Paulauskas, P. Ercius, J. Varley, J. Bailey, G. Zapalac, D. Poplavskyy, N. Mackie, A. Bayman, R. Klie, V. Lordi, A. Rockett, “Cd doping at PVD-CdS/CuInGaSe₂ heterojunctions,” Solar Energy Materials and Solar Cells 164, 128 (2017).
• X.Q. He, J.B. Varley, P. Ercius, T. Erikson, J. Bailey, G. Zapalac, D. Poplavskyy, N. Mackie, A. Bayman, V. Lordi, and A. Rockett, “Intermixing and Formation of Cu-Rich Secondary Phases at Sputtered CdS/CuInGaSe₂ Heterojunctions,” IEEE J. of Photovoltaics 6, 1308 (2016).
• K.E. Kweon, D. Åberg, and V. Lordi, “First-principles study of atomic and electronic structures of 60° perfect and 30°/90° partial glide dislocations in CdTe,” Physical Review B 93, 174109 (2016).
• J.B. Varley, V. Lordi, X. He, and A. Rockett, “First principles calculations of point defect diffusion in CdS buffer layers: Implications for Cu(In,Ga)(Se,S)₂ and Cu₂ZnSn(Se,S)₄-based thin-film photovoltaics,”Journal of Applied Physics 119, 025703 (2016).
• N. Adelstein, C.S. Olson, and V. Lordi, “Hole traps in sodium silicate: first-principles calculations of the mobility edge,” Journal of Non-Crystalline Solids 430, 9 (2015).
• J.B. Varley, A.M. Conway, L.F. Voss, E. Swanberg, R.T. Graff, R.J. Nikolic, S.A. Payne, V. Lordi, and A.J. Nelson, “Effect of chlorination on the TlBr band gap for improved room temperature radiation detectors,” Physica Status Solidi B 252, 1266 (2015). [Back Cover article]
• M.T. Ong, O. Verners, E.W. Draeger, A.C.T. van Duin, V. Lordi, and J. Pask, “Lithium Ion Solvation and Diffusion in Bulk Organic Electrolytes from First Principles and Classical Reactive Molecular Dynamics,” Journal of Physical Chemistry B 119, 1535 (2014).
• P. Soderlind, P.E.A. Turchi, A. Landa, and V. Lordi, “Ground-state properties of rare-earth metals: An evaluation of density-functional theory,” Journal of Physics: Condensed Matter 26, 416001 (2014).
• J.B. Varley and V. Lordi, “Intermixing at the absorber-buffer layer interface in thin-film solar cells: The electronic effects of point defects in Cu(In,Ga)(Se,S)₂ and Cu₂ZnSn(Se,S)₄ devices,” Journal of Applied Physics 116, 063505 (2014).
• X.Q. He, G. Brown, K. Demirkan, N. Mackie, V. Lordi, A. Rockett, “Microstructural and Chemical Investigation of PVD-CdS/PVD-CuIn_1–xGa_xSe₂ Heterojunctions: A Transmission Electron Microscopy Study,” IEEE J. of Photovoltaics 4, 1625 (2014).
• D. Lee, J.L. Dubois, and V. Lordi, “Identification of the Local Sources of Paramagnetic Noise in Superconducting Qubit Devices Fabricated on alpha-Al2O3 Substrates Using Density-Functional Calculations,” Physical Review Letters (Editor’s Selection) 112, 017001 (2014).
• P. Söderlind, B. Sadigh, V. Lordi, A. Landa and P.E.A. Turchi, “Electron correlation and relativity of the 5f electrons in the U–Zr alloy system,” Journal of Nuclear Materials 444, 356 (2014).
• J.B. Varley and V. Lordi, “Electrical properties of point defects in CdS and ZnS,” Applied Physics Letters 103, 102103 (2013).
• G. Wang, Y. Ling, X. Lu, F. Qian, Y. Tong, J.Z. Zhang, V. Lordi, C.R. Leão, and Y. Li, “Computational and Photoelectrochemical Study of Hydrogenated Bismuth Vanadate,” Journal of Physical Chemistry C 117, 10957 (2013).
• D. Åberg, P. Erhart, and V. Lordi, “Contributions of point defects, chemical disorder, and thermal vibrations to electronic properties of Cd_1−xZn_xTe alloys,” Physical Review B 88, 045201 (2013).
• V. Lordi, “Point Defects in Cd(Zn)Te and TlBr: Theory,” Journal of Crystal Growth (invited special issue) 379, 84 (2013).
• C. Rocha-Leão and V. Lordi, “Ionic current and polarization effect in TlBr,” Physical Review B 87, 081202(R) (2013).
• C. Rocha-Leão and V. Lordi, “Simultaneous Control of Ionic and Electronic Conductivity in Materials: Thallium Bromide Case Study,” Physical Review Letters 108, 246604 (2012).
• C. Rocha-Leão and V. Lordi, “Ab initio guided optimization of GaTe for radiation detection applications,” Physical Review B 84, 165206 (2011).
• V. Lordi, P. Erhart, and D. Åberg, “Charge carrier scattering by defects in semiconductors,” Physical Review B 81, 235204 (2010).
• P. Erhart, D. Åberg, B.W. Sturm, K.-J. Wu, and V. Lordi, “Theory-Guided Growth of Aluminum Antimonide Single Crystals with Optimal Properties for Radiation Detection,” Applied Physics Letters 97, 142104 (2010).
• P. Erhart, D. Åberg, and V. Lordi, “Extrinsic point defects in aluminum antimonide,” Physical Review B 81, 195216 (2010).
• N.P. Zaitseva, J. Newby, S. Hamel, L. Carman, M. Faust, V. Lordi, N.J. Cherepy, W. Stoeffl, S.A. Payne, “Neutron detection with single crystal organic scintillators,” Proc. SPIE 7449, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XI, 744911 (2009).
• D. Åberg, P. Erhart, A.J. Williamson, and V. Lordi, “Intrinsic point defects in aluminum antimonide,” Physical Review B 77(16), 165206 (2008).
• T.T.M. Vo, A.J. Williamson, V. Lordi, G. Galli, “Atomistic design of thermoelectric properties of silicon nanowires,” Nano Letters 8(4), 1111 (2008).
• V. Lordi, H.B. Yuen, S.R. Bank, M.A. Wistey, S. Friedrich, and J.S. Harris, “Nearest neighbor distributions in GaInNAs(Sb) upon annealing,” Physical Review B 71(12), 125309 (2005).
• V. Lordi, H. Yuen, S. Bank, and J.S. Harris, “Quantum confined Stark effect of GaInNAs(Sb) quantum wells at 1300-1600 nm,” Applied Physics Letters 85(6), 902 (2004).
• V. Lordi, V. Gambin, S. Friedrich, T. Funk, T. Takizawa, K. Uno, and J.S. Harris, “Nearest-neighbor configuration in (GaIn)(NAs) probed by x-ray absorption spectroscopy,” Physical Review Letters 90(14), 145505 (2003).
• V. Lordi, N. Yao, and J. Wei, “Method for Supporting Platinum on Single-Walled Carbon Nanotube for a Selective Hydrogenation Catalyst,” Chemistry of Materials 13(3), 733 (2001).