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Fundamental and Computational Sciences Directorate

Staff information


Wayne Hess

Physical Sciences Division
Scientist, TL
Pacific Northwest National Laboratory
PO Box 999
MSIN: K8-88
Richland, WA 99352


My research is centered on laser-excitation of solids and surfaces. We have ongoing research programs in laser desorption from wide-band gap materials, metal oxides, and semiconductors. Many of the key photophysical processes in laser solid interactions, such as electron/hole-pair generation and recombination, exciton relaxation, and electron-phonon interactions, occur on an ultrafast time-scale. Therefore, we have developed femtosecond laser techniques, in addition to nanosecond studies, to clarify the role of ultrafast phenomena involved in laser material interactions and excited-state condensed-phase processes. Recently, we initiated a program to explore dynamics of mesoscopic surface structures. In particular, we are studying localized and propagating surface plasmons using photoemission electron microscopy and both surface and tip enhanced Raman spectroscopy (SERS and TERS). My team and I are actively engaged in collaboration with theory groups to understand the dynamical details of localized and propagating plasmons and their relationship to single-molecule Raman scattering. Our ultimate goal is a broad-based mechanistic understanding of excited-state dynamics of surface structures, plasmonics, and ultrasensitive chemical imaging. We have demonstrated single-molecule detection and designed manipulation (e.g., focusing) of propagating plasmons. Ultimately, our efforts are directed toward providing the radiation and analytical chemistry research needs required by the U.S. Department of Energy's energy and environmental restoration missions.

Currently, I am serving as Interim Director of the Physical Sciences Division.

Research Interests

  • Laser desorption and surface modification
  • Surface and tip-enhanced Raman spectroscopy
  • Localized and propagating surface plasmon dynamics

Education and Credentials

  • Ph.D. Physical Chemistry, University of Colorado, Boulder, CO, January, 1988
  • M.S. Chemical Physics, University of Oregon, Eugene, OR, May 1983
  • B.A. Chemistry, University of Colorado, Boulder, CO, May 1981.

Affiliations and Professional Service

  • American Chemical Society
  • American Physical Society
  • SPIE

Awards and Recognitions

  • American Physical Society Fellow, 2012
  • Co-Chairman Eighth International Conference on Laser Ablation (COLA 05)
  • Associate Editor: Laser Chemistry
  • International Steering Committee, International Conference on Laser Ablation
  • Vice-chair Gordon Research Conference: Laser Interactions with Materials

PNNL Publications


  • Davidson RB, JI Ziegler, G Vargas, SM Avanesyan, Y Gong, WP Hess, and RF Haglund Jr.. 2015. "Efficient Forward Second-Harmonic Generation from Planar Archimedean Nanospirals." Nanophotonics 4(1):108-113.  doi:10.1515/nanoph-2015-0002
  • Droubay TC, L Kong, SA Chambers, and WP Hess. 2015. "Work Function Reduction by BaO: Growth of Crystalline Barium Oxide on Ag(001) and Ag(111) Surfaces." Surface Science 632:201-206.  doi:10.1016/j.susc.2014.07.010
  • El-Khoury PZ, Y Gong, P Abellan, BW Arey, AG Joly, D Hu, JE Evans, ND Browning, and WP Hess. 2015. "Tip-Enhanced Raman Nanographs: Mapping Topography and Local Electric Fields." Nano Letters 15(4):2385-2390.  doi:10.1021/acs.nanolett.5b00609
  • Gong Y, AG Joly, D Hu, PZ El-Khoury, and WP Hess. 2015. "Ultrafast Imaging of Surface Plasmons Propagating on a Gold Surface." Nano Letters 15(5):3472-3478.  doi:10.1021/acs.nanolett.5b00803
  • Halliday MT, WP Hess, and AL Shluger. 2015. "Structure and properties of electronic and hole centers in CsBr from theoretical calculations." Journal of Physics: Condensed Matter 27(24):245501.  doi:10.1088/0953-8984/27/24/245501
  • Kong L, AG Joly, TC Droubay, and WP Hess. 2015. "Quantum Efficiency Enhancement in CsI/Metal Photocathodes." Chemical Physics Letters 621:155-159.  doi:10.1016/j.cplett.2015.01.010


  • Cao H, W He, Y Mao, X Lin, K Ishikawa, JH Dickerson, and WP Hess. 2014. "Recent progress in degradation and stabilization of organic solar cells." Journal of Power Sources 264:168-183.  doi:10.1016/j.jpowsour.2014.04.080
  • Droubay TC, SA Chambers, AG Joly, WP Hess, K Nemeth, KC Harkay, and L Spentzouris. 2014. "Metal-Insulator Photocathode Heterojunction for Directed Electron Emission." Physical Review Letters 112(6):067601(5).  doi:10.1103/PhysRevLett.112.067601
  • El-Khoury PZ, and WP Hess. 2014. "Vibronic Raman Scattering at the Quantum Limit of Plasmons." Nano Letters 14(7):4114-4118.  doi:10.1021/nl501690u
  • El-Khoury PZ, E Khon, Y Gong, AG Joly, P Abellan, JE Evans, ND Browning, D Hu, M Zamkov, and WP Hess. 2014. "Electric Field Enhancement in a Self-Assembled 2D Array of Silver Nanospheres." Journal of Chemical Physics 141(21):Article No. 214308.  doi:10.1063/1.4902905
  • El-Khoury PZ, K Honkala, and WP Hess. 2014. "Electronic and Vibrational Properties of Meso-Tetraphenylporphyrin on Silver Substrates." Journal of Physical Chemistry A 118(37):8115-8123.  doi:10.1021/jp412360b
  • El-Khoury PZ, TW Ueltschi, AL Mifflin, D Hu, and WP Hess. 2014. "Frequency Resolved Nanoscale Chemical Imaging of 4,4'-Dimercaptostilbene on Silver." Journal of Physical Chemistry C 118(47):27525-27530.  doi:10.1021/jp509082c
  • Gong Y, AG Joly, L Kong, PZ El-Khoury, and WP Hess. 2014. "High Brightness Plasmon-Enhanced Nanostructured Gold Photoemitters." Physical Review Applied 2(6):Article No. 064012.  doi:10.1103/PhysRevApplied.2.064012
  • Gong Y, AG Joly, PZ El-Khoury, and WP Hess. 2014. "Interferometric Plasmonic Lensing with Nanohole Arrays." Journal of Physical Chemistry Letters 5(24):4243-4248.  doi:10.1021/jz502296n
  • Gong Y, AG Joly, PZ El-Khoury, and WP Hess. 2014. "Nonlinear Photoemission Electron Micrographs of Plasmonic Nanoholes in Gold Thin Films." Journal of Physical Chemistry C 118(44):25671-25676.  doi:10.1021/jp509900h
  • Kong L, AG Joly, TC Droubay, Y Gong, and WP Hess. 2014. "Enhanced Quantum Efficiency From Hybrid Cesium Halide/Copper Photocathode." Applied Physics Letters 104(17):Article No. 171106.  doi:10.1063/1.4874339


  • Devaraj A, RJ Colby, WP Hess, DE Perea, and S Thevuthasan. 2013. "Role of Photoexcitation and Field Ionization in the Measurement of Accurate Oxide Stoichiometry by Laser-Assisted Atom Probe Tomography." The Journal of Physical Chemistry Letters 4(6):993-998.  doi:10.1021/jz400015h
  • El-Khoury PZ, and WP Hess. 2013. "Raman Scattering from 1,3-Propanedithiol at a Hot Spot: Theory Meets Experiment." Chemical Physics Letters 581:57-63.  doi:10.1016/j.cplett.2013.05.066
  • El-Khoury PZ, D Hu, and WP Hess. 2013. "Junction Plasmon-Induced Molecular Reorientation." Journal of Physical Chemistry Letters 4(20):3435-3439.  doi:10.1021/jz401838b
  • El-Khoury PZ, D Hu, VA Apkarian, and WP Hess. 2013. "Raman Scattering at Plasmonic Junctions Shorted by Conductive Molecular Bridges." Nano Letters 13(4):1858-1861.  doi:10.1021/nl400733r
  • El-Khoury PZ, EJ Bylaska, and WP Hess. 2013. "Time Domain Simulations of Chemical Bonding Effects in Surface-Enhanced Spectroscopy." Journal of Chemical Physics 139(17):Article No. 174303.  doi:10.1063/1.4827455
  • El-Khoury PZ, SJ Peppernick, D Hu, AG Joly, and WP Hess. 2013. "The Origin of Surface-Enhanced Raman Scattering of 4,4' -Biphenyldicarboxylate on Silver Substrates." Journal of Physical Chemistry C 117(14):7260-7268.  doi:10.1021/jp401026x
  • Halliday MT, AG Joly, WP Hess, P Sushko, and AL Shluger. 2013. "Mechanisms of Photodesorption of Br Atoms from CsBr Surfaces." Journal of Physical Chemistry C 117(26):13502-13509.  doi:10.1021/jp4036343
  • He W, S VilayurGanapathy, AG Joly, TC Droubay, SA Chambers, JR Maldonado, and WP Hess. 2013. "Comparison of CsBr and KBr coated Cu photocathodes: Effects of laser irradiation and work function changes." Applied Physics Letters 102(7):Article No. 071604.  doi:10.1063/1.4793214
  • Lin J, W He, S Vilayur Ganapathy, SJ Peppernick, B Wang, S Palepu, M Remec, WP Hess, AB Hmelo, ST Pantelides, and J Dickerson. 2013. "Growth of solid and hollow gold particles through the thermal annealing of nanoscale patterned thin films." ACS Applied Materials & Interfaces 5(22):11590-11596.  doi:10.1021/am402633u
  • Peppernick SJ, AG Joly, KM Beck, and WP Hess. 2013. "Plasmon-Induced Optical Field Enhancement studied by Correlated Scanning and Photoemission Electron Microscopy." Journal of Chemical Physics 138(15):Article No. 154701.  doi:10.1063/1.4799937
  • Peppernick SJ, AG Joly, KM Beck, WP Hess, J Wang, YC Wang, and W Wei. 2013. "Photoemission Electron Microscopy of a Plasmonic Silver Nanoparticle Trimer." Applied Physics A, Materials Science and Processing 112(1):35-39.  doi:10.1007/s00339-012-7316-5
  • Polyakov A, C Senft, KF Thompson, J Feng, S Cabrini, PJ Schuck, H Padmore, SJ Peppernick, and WP Hess. 2013. "Plasmon-enhanced photocathode for high brightness and high repetition rate x-ray sources." Physical Review Letters 110(7):Article No. 076802.  doi:10.1103/PhysRevLett.110.076802
  • Vilayur Ganapathy S, A Devaraj, RJ Colby, A Pandey, T Varga, V Shutthanandan, S Manandhar, PZ El-Khoury, AN Kayani, WP Hess, and S Thevuthasan. 2013. "Subsurface Synthesis and Characterization of Ag Nanoparticles Embedded in MgO." Nanotechnology 24(9):Article No. 095707.  doi:10.1088/0957-4484/24/9/095707
  • Vilayur Ganapathy S, MI Nandasiri, AG Joly, PZ El-Khoury, T Varga, GW Coffey, B Schwenzer, A Pandey, AN Kayani, WP Hess, and S Thevuthasan. 2013. "Silver nanorod arrays for photocathode applications." Applied Physics Letters 103(16):Article No. 161112.  doi:10.1063/1.4825262


  • Peppernick SJ, AG Joly, KM Beck, and WP Hess. 2012. "Near-Field Focused Photoemission from Polystyrene Microspheres Studied with Photoemission Electron Microscopy." Journal of Chemical Physics 137(1):124202-1/9.  doi:10.1063/1.4730598
  • Shutthanandan V, Z Zhu, ML Stutzman, F Hannon, C Hernandez-Garcia, MI Nandasiri, SVNT Kuchibhatla, S Thevuthasan, and WP Hess. 2012. "Surface Science Analysis of GaAs Photocathodes Following Sustained Electron Beam Delivery." Physical Review Special Topics - Accelerators and Beams 15(6):063501.  doi:10.1103/PhysRevSTAB.15.063501


  • Fredricksen CJ, DR Panjwani, JP Arnold, PN Figueiredo, FK Rezaie, JE Colwell, K Baillie, SJ Peppernick, AG Joly, KM Beck, WP Hess, and RE Peale. 2011. "Plasmonic enhancement of thin-film solar cells using gold-black coatings." In Next Generation (Nano) Photonic and Cell Tehcnologies for Solar Energy Conversion II, August 21, 2011, San Diego, California. Proceedings of the SPIE, vol. 8111, ed. L Tsakalakos, p. Article No. 811106.  SPIE, Bellingham, WA.  doi:10.1117/12.893620
  • Peppernick SJ, AG Joly, KM Beck, and WP Hess. 2011. "Plasmonic Field Enhancement of Individual Nanoparticles by Correlated Scanning and Photoemission Electron Microscopy." Journal of Chemical Physics 134(3):034507-1/7.  doi:10.1063/1.3543714
  • Sushko PV, AL Shluger, AG Joly, KM Beck, and WP Hess. 2011. "Exciton-driven highly hyperthermal O-atom desorption from nanostructured CaO." Journal of Physical Chemistry C 115(3):692-699.  doi:10.1021/jp1078423


  • Beck KM, AG Joly, and WP Hess. 2010. "Effect of Surface Charge on Laser-induced Neutral Atom Desorption." Applied Physics A, Materials Science and Processing 101(1):61-64.  doi:10.1007/s00339-010-5758-1
  • Joly AG, KM Beck, and WP Hess. 2010. "Surface-Specific Laser Matter Interactions and Dynamics." In International Symposium on High Power Laser Ablation, April 18-22, 2010, Santa Fe, NM: AIP Conference Proceedings, vol. 1278, no. 1, ed. C Phipps, pp. 90-97.  American Institute of Physics, Melville, NY.  doi:10.1063/1.3507187
  • Xiong G, R Shao, SJ Peppernick, AG Joly, KM Beck, WP Hess, M Cai, J Duchene, JY Wang, and W Wei. 2010. "Materials Applications of Photoelectron Emission Microscopy." JOM. The Journal of the Minerals, Metals and Materials Society 62(12):90-93.  doi:10.1007/s11837-010-0189-1


  • Beck KM, AG Joly, and WP Hess. 2009. "Two-color Laser Desorption of Nanostructured MgO Thin Films." Applied Surface Science 255(24):9562-9565.  doi:10.1016/j.apsusc.2009.04.089
  • Govind N, PV Sushko, WP Hess, M Valiev, and K Kowalski. 2009. "Excitons in Potassium Bromide: A Study using Embedded Time-dependent Density Functional Theory and Equation-of-Motion Coupled Cluster Methods." Chemical Physics Letters 470(4-6):353-357.  doi:10.1016/j.cplett.2009.01.073
  • Joly AG, KM Beck, and WP Hess. 2009. "Photodesorption of excited iodine atoms from KI (100)." Journal of Chemical Physics 131(14):144509-1/6. 
  • Khan EH, SC Langford, JT Dickinson, LA Boatner, and WP Hess. 2009. "Photoinduced Formation of Zinc Nanoparticles by UV Laser Irradiation of ZnO." Langmuir 25(4):1930-1933. 
  • Trevisanutto PE, PV Sushko, KM Beck, AG Joly, WP Hess, and AL Shluger. 2009. "Excitation, Ionization, and Desorption: How Sub-band gap Photons Modify the Structure of Oxide Nanoparticles." Journal of Physical Chemistry C 113(4):1274-1279. 


  • Beck KM, AG Joly, OE Diwald, S Stankic, PE Trevisanutto, PV Sushko, AL Shluger, and WP Hess. 2008. "Energy and Site Selectivity in O-Atom Photodesorption from Nanostructured MgO." Surface Science 602(11):1968-1973.  doi:10.1016/j.susc.2008.03.046
  • Joly AG, KM Beck, and WP Hess. 2008. "Electronic Energy Transfer on CaO Surfaces." Journal of Chemical Physics 129(12):124704.  doi:10.1063/1.2980049


  • Cai M, SC Langford, JT Dickinson, G Xiong, TC Droubay, AG Joly, KM Beck, and WP Hess. 2007. "An In Situ Study of the Martensitic Transformation in Shape Memory Alloys Using Photoemission Electron Microscopy." Journal of Nuclear Materials 361(2-3):306-312.  doi:10.1016/j.jnucmat.2006.12.008
  • Cai M, SC Langford, MJ Wu, WM Huang, G Xiong, TC Droubay, AG Joly, K Beck, WP Hess, and JT Dickinson. 2007. "Study of Martensitic Phase transformation in a NiTiCu Thin Film Shape Memory Alloy Using Photoelectron Emission Microscopy." Advanced Functional Materials 17(1):161-167.  doi:10.1002/adfm.200600611
  • Hess WP, PR Herman, DW Bauerle, and H Koinuma. 2007. The 8th International Conference on Laser Ablation (COLA' 05); Journal of Physics: Conference Series , vol. 59, IOP Publishing, Bristol, United Kingdom. 
  • Joly AG, G Xiong, CM Wang, DE McCready, KM Beck, and WP Hess. 2007. "Synthesis and Photoexcited Charge Carrier Dynamics of beta-FeOOH Nanorods." Applied Physics Letters 90(10):Art. No. 103504.  doi:10.1063/1.2711395
  • Wei W, G Xiong, Y Sun, AG Joly, KM Beck, JM White, and WP Hess. 2007. "Real Time Study of Cu Diffusion Through a Ru Thin Film by Photoemission Electron Microscopy (PEEM)." In Materials, technology and reliability of low-k dielectrics and copper interconnects. Materials Research Society Symposium Proceedings; 2006, vol. 914, ed. Ting Y Tsui, pp. 185-190 (Paper no. 0914-F05-07).  Material Research Society, Warrendale, PA. 
  • Wei W, SL Parker, Y Sun, JM White, G Xiong, AG Joly, KM Beck, and WP Hess. 2007. "Study of Copper Diffusion Through Ruthenium Thin Film by Photoemission Electron Microscopy." Applied Physics Letters 90:111906.  doi:10.1063/1.2712832
  • Xiong G, R Shao, TC Droubay, AG Joly, KM Beck, SA Chambers, and WP Hess. 2007. "Photoemission Electron Microscopy of TiO2 Anatase Films Embedded with Rutile Nanocrystals." Advanced Functional Materials 17(13):2133-2138.  doi:10.1002/adfm.200700146


  • Beck KM, M Henyk, CM Wang, PE Trevisanutto, P Sushko, WP Hess, and AL Shluger. 2006. "Site-Specific Laser Modification of MgO nanoclusters: Towards Atomic-Scale Surface Structuring." Physical Review. B, Condensed Matter 74:045404 (5 pages). 
  • Joly AG, JR Williams, SA Chambers, G Xiong, WP Hess, and DM Laman. 2006. "Carrier Dynamics in a-Fe2O3 (0001) Thin Films and Single Crystals Probed by Femtosecond Transient Absorption and Reflectivity." Journal of Applied Physics 99(5):Article: 053521 (6 pages). 
  • Joly AG, M Henyk, KM Beck, PE Trevisanutto, PV Sushko, WP Hess, and AL Shluger. 2006. "Probing Electron Transfer Dynamics at MgO Surfaces by Mg-Atom Desorption." Journal of Physical Chemistry B 110(37):18093-18096.  doi:10.1021/jp064092b
  • Tanimura K, E Inami, J Kanasaki, and WP Hess. 2006. "Two-Hole Localization Mechanism for Electron Bond Rupture of Surface Atoms by Laser-Induced Valence Excitation of Semiconductors." Physical Review. B, Condensed Matter and Materials Physics 74(3):Art. No. 035337.  doi:10.1103/PhysRevB.74.035337
  • Xiong G, AG Joly, GR Holtom, CM Wang, DE McCready, KM Beck, and WP Hess. 2006. "Excited Carrier Dynamics of a-Cr2O3/a-Fe2O3 Core-Shell Nanostructures." Journal of Physical Chemistry B 110(34):16937-16940.  doi:10.1021/jp062507n S1520-6106(06)02507-7
  • Xiong G, AG Joly, KM Beck, and WP Hess. 2006. "Laser-Induced Oxygen Vacancy Formation and Diffusion on TiO2(110) Surfaces Probed by Photoemission Electron Microscopy." Physica Status Solidi C 3(10):3598-3602. 
  • Xiong G, AG Joly, KM Beck, WP Hess, M Cai, SC Langford, and JT Dickinson. 2006. "In Situ Photoelectron Emission Microscopy of a Thermally Induced Martensitic Transformation in a CuZnAI Shape Memory Alloy." Applied Physics Letters 88(9):Art. No. 091910. 
  • Xiong G, AG Joly, WP Hess, M Cai, and JT Dickinson. 2006. "Introduction to Photoelectron Emission Microscopy: Principles and Applications." Journal of Chinese Electron Microscopy Society 25(1):15-25. 


  • Henyk M, KM Beck, MH Engelhard, AG Joly, WP Hess, and JT Dickinson. 2005. "Surface Electronic Properties and Site-Specific Laser Desorption Processes of Highly Structured Nanoporous MgO Thin Films." Surface Science 593(1-3):242-247. 
  • Hess WP, AG Joly, KM Beck, M Henyk, PV Sushko, PE Trevisanutto, and AL Shluger. 2005. "Laser Control of Desorption Through Selective Surface Excitation." Journal of Physical Chemistry B 109(42):19563-19578.  doi:10.1021/jp0523672
  • Nwe KH, SC Langford, JT Dickinson, and WP Hess. 2005. "Interaction of Wide-Band-Gap Single Crystals with 248-nm Excimer Laser Irradiation: X. Laser-Induced Near-Surface Absorption in Single-Crystal NaC1." Journal of Applied Physics 97(4):Article no. 043501. 
  • Nwe KH, SC Langford, JT Dickinson, and WP Hess. 2005. "Interaction of Wide-Band-Gap Single Crystals With 248-nm Excimer Laser Radiation: XI. The Effect of Water Vapor and Temperature on Laser Desorption of Neutral Atoms From Sodium Chloride." Journal of Applied Physics 97:043502-1-10. 
  • Trevisanutto PE, PV Sushko, AL Shluger, KM Beck, M Henyk, AG Joly, and WP Hess. 2005. "A Mechanism of Photo-Induced Desorption of Oxygen Atoms From MgO Nano-Crystals." Surface Science 593(1-3):210-220. 


  • Beck KM, AG Joly, NF Dupuis, P Perozzo, WP Hess, PV Sushko, and AL Shluger. 2004. "Laser Control of Product Electronic State: Desorption from Alkali Halides." Journal of Chemical Physics 120(5):2456-2463. 
  • Espana AL, AG Joly, WP Hess, and JT Dickinson. 2004. "Laser-Induced Damage of Calcium Fluoride." Journal of Undergraduate Research Volume IV, 2004:60-65. 
  • Hess WP, AG Joly, KM Beck, PV Sushko, and AL Shluger. 2004. "Determination of Surface Exciton Energies by Velocity Resolved Atomic Desorption." Surface Science 564(1-3):62-70. 
  • Joly AG, WP Hess, and KM Beck. 2004. "Time-Resolved Femtosecond Laser Desorption from Alkali Halide Crystals." In High-Power Laser Ablation V. Proceedings of the SPIE, vol. 5448, ed. Claude R. Phipps, pp. 532-537.  International Society Optical Engineering, Bellingham. 
  • Tanimura K, and WP Hess. 2004. "Temperature-Dependent Yield of Frenkel-Pairs Generated by Valence Excitation in NaCl." Physical Review. B, Condensed Matter 69(15):155102-1-155102-7. 


  • Joly AG, KM Beck, M Henyk, WP Hess, PV Sushko, and AL Shluger. 2003. "Surface Electronic Spectra Detected by Atomic Desorption." Surface Science 544(1):L683-L688. 


  • Hess WP, AG Joly, KM Beck, DP Gerrity, PV Sushko, and AL Shluger. 2002. "Solid-State Halogen Atom Source for Chemical Dynamics and Etching." Applied Physics Letters 81(6):1140-1142. 


  • Reeder RJ, M Nugent , CD Tait, DE Morris, SM Heald, KM Beck, WP Hess, and A Lanzirotti. 2001. "Coprecipitation of Uranium (VI) with Calcite: XAFS, Micro-XAS,and Luminescence Characterization ." Geochimica et Cosmochimica Acta 65(20):3491-3503. 




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