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Erin Ratcliff, PhD

Assistant Professor of Materials Science and Engineering

Degrees and Appointments

  • Certificate Entrepreneurship_University of Arizona, Tucson, Arizona, USA
  • Ph.D. Physical Chemistry_Iowa State University, Ames, Iowa, USA
  • B.A. Chemistry, Mathematics, Statistics_St. Olaf College, Northfield, Minnesota, U.S.A

Awards and Honors

  • Ten at Ten People of Energy Frontier Research Centers
  • Excellence at the Student Interface – Most Supportive Junior Faculty
  • Office of Naval Research Summer Faculty Fellow

Research Topics

In the Ratcliff group, we are broadly interested in materials synthesis, structural control, processing, and transport phenomena of low cost semiconducting materials and interfaces.  Our particular emphasis is organic-based electronic devices. Polymeric and organic semiconductors offer mechanical flexibility and tailorable properties through synthesis, which makes them exceptionally promising in next-generation electronics.

Our overarching goals are developing exciting opportunities in flexible devices for bioelectronics and energy harvesting and storage, all with reduced manufacturing cost and lessened environmental impact. To achieve this goal, we must understand the molecular-level composition and structure controlling charge transfer and charge transport properties. 

Scholarly Contributions

Journals/Publications
Arnold, S. P., Harris, J. K., Neelamraju, B., Rudolph, M., & Ratcliff, E. L. (2019). Microstructure-dependent electrochemical properties of chemical-vapor deposited poly(3,4-ethylenedioxythiophene) (PEDOT) films. SYNTHETIC METALS, 253, 26-33.
Daviddi, E., Chen, Z., Massani, B. B., Lee, J., Bentley, C. L., Unwin, P. R., & Ratcliff, E. L. (2019). Nanoscale Visualization and Multiscale Electrochemical Analysis of Conductive Polymer Electrodes. ACS NANO, 13(11), 13271-13284.
Harris, J. K., Neelamraju, B., & Ratcliff, E. L. (2019). Intersystem Subpopulation Charge Transfer and Conformational Relaxation Preceding in Situ Conductivity in Electrochemically Doped Poly(3-hexylthiophene) Electrodes. CHEMISTRY OF MATERIALS, 31(17), 6870-6879.
Harris, J., Bickford, J., Cho, P., Coppock, M., Farrell, M., Holthoff, E., & Ratcliff, E. (2019). Approaching Single Molecule Sensing: Predictive Sweat Sensor Design for Ultra-Low Limits of Detection. CHEMICAL, BIOLOGICAL, RADIOLOGICAL, NUCLEAR, AND EXPLOSIVES (CBRNE) SENSING XX, 11010. doi:10.1117/12.2518543
Ndione, P. F., Ratcliff, E. L., Dey, S. R., Warren, E. L., Peng, H., Holder, A. M., Lany, S., Gorman, B. P., Al-Jassim, M. M., Deutsch, T. G., Zakutayev, A., & Ginley, D. S. (2019). High-Throughput Experimental Study of Wurtzite Mn1-xZnxO Alloys for Water Splitting Applications. ACS OMEGA, 4(4), 7436-7447.
Rudolph, M., Harris, J. K., & Ratcliff, E. L. (2019). Predicting limits of detection in real-time sweat-based human performance monitoring. SMART BIOMEDICAL AND PHYSIOLOGICAL SENSOR TECHNOLOGY XV, 11020.
Rudolph, M., Harris, J. K., & Ratcliff, E. L. (2019). Printable transistors for wearable sweat sensing. SMART BIOMEDICAL AND PHYSIOLOGICAL SENSOR TECHNOLOGY XV, 11020.
Watts, K. E., Neelamraju, B., Ratcliff, E. L., & Pemberton, J. E. (2019). Stability of Charge Transfer States in F(4)TCNQ-Doped P3HT. CHEMISTRY OF MATERIALS, 31(17), 6986-6994.
Watts, K. E., Nguyen, T., de, V., Neelamraju, B., Anderson, M. A., Braunecker, W. A., Ferguson, A. J., Larsen, R. E., Larson, B. W., Owczarczyk, Z. R., Pfeilsticker, J. R., Pemberton, J. E., & Ratcliff, E. L. (2019). Stability of push-pull small molecule donors for organic photovoltaics: spectroscopic degradation of acceptor endcaps on benzo[1,2-b:4,5-b ']dithiophene cores. JOURNAL OF MATERIALS CHEMISTRY A, 7(34), 19984-19995.
Neelamraju, B., Rudolph, M., & Ratcliff, E. L. (2018). Controlling the Kinetics of Charge Transfer at Conductive Polymer/Liquid Interfaces through Microstructure. JOURNAL OF PHYSICAL CHEMISTRY C, 122(37), 21210-21215.
Neelamraju, B., Watts, K. E., Pemberton, J. E., & Ratcliff, E. L. (2018). Correlation of Coexistent Charge Transfer States in F(4)TCNQ-Doped P3HT with Microstructure. JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 9(23), 6871-6877.
Placencia, D., Lee, P., Tischler, J. G., & Ratcliff, E. L. (2018). Energy Level Alignment of Molybdenum Oxide on Colloidal Lead Sulfide (PbS) Thin Films for Optoelectronic Devices. ACS APPLIED MATERIALS & INTERFACES, 10(30), 24981-24986.
Pemberton, J., Sang, L., Watts, K., Nguyen, T., & Ratcliff, E. (2017). Organic semiconductor interfaces in optoelectronic devices: Undesirable chemistry galore!. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 253.
Rudolph, M., & Ratcliff, E. L. (2017). Normal and inverted regimes of charge transfer controlled by density of states at polymer electrodes. NATURE COMMUNICATIONS, 8.
Steirer, K. X., Ou, K. L., Armstrong, N. R., & Ratcliff, E. L. (2017). Critical Interface States Controlling Rectification of Ultrathin NiO- ZnO p-n Heterojunctions. ACS APPLIED MATERIALS & INTERFACES, 9(36), 31111-31118.
McLachlan, M. A., & Ratcliff, E. L. (2016). Metal Oxide Heterointerfaces in Hybrid Electronic Platforms. ADVANCED MATERIALS, 28(20), 3801-3801.
Ratcliff, E. L., Shallcross, R. C., & Armstrong, N. R. (2016). Introduction: Electronic Materials. CHEMICAL REVIEWS, 116(21), 12821-12822.
Cowan, S. R., Li, J. V., Olson, D. C., & Ratcliff, E. L. (2015). Contact-Induced Mechanisms in Organic Photovoltaics: A Steady-State and Transient Study. ADVANCED ENERGY MATERIALS, 5(1).
Fei, Z., Boufflet, P., Wood, S., Wade, J., Moriarty, J., Gann, E., Ratcliff, E. L., McNeill, C. R., Sirringhaus, H., Kim, J., & Heeney, M. (2015). Influence of Backbone Fluorination in Regioregular Poly(3-alkyl-4-fluoro)thiophenes. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 137(21), 6866-6879.
Lin, H., MacDonald, G. A., Shi, Y., Polaske, N. W., McGrath, D. V., Marder, S. R., Armstrong, N. R., Ratcliff, E. L., & Saavedra, S. S. (2015). Influence of Molecular Orientation on Charge-Transfer Processes at Phthalocyanine/Metal Oxide Interfaces and Relationship to Organic Photovoltaic Performance. JOURNAL OF PHYSICAL CHEMISTRY C, 119(19), 10304-10313.
Oosterhout, S. D., Kopidakis, N., Owczarczyk, Z. R., Braunecker, W. A., Larsen, R. E., Ratcliff, E. L., & Olson, D. C. (2015). Integrating theory, synthesis, spectroscopy and device efficiency to design and characterize donor materials for organic photovoltaics: a case study including 12 donors. JOURNAL OF MATERIALS CHEMISTRY A, 3(18), 9777-9788.
Shallcross, R. C., Stubhan, T., Ratcliff, E. L., Kahn, A., Brabec, C. J., & Armstrong, N. R. (2015). Quantifying the Extent of Contact Doping at the Interface between High Work Function Electrical Contacts and Poly(3-hexylthiophene) (P3HT). JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 6(8), 1303-1309.
Steirer, K. X., Richards, R. E., Sigdel, A. K., Garcia, A., Ndione, P. F., Hammond, S., Baker, D., Ratcliff, E. L., Curtis, C., Furtak, T., Ginley, D. S., Olson, D. C., Armstrong, N. R., & Berry, J. J. (2015). Nickel oxide interlayer films from nickel formate-ethylenediamine precursor: influence of annealing on thin film properties and photovoltaic device performance. JOURNAL OF MATERIALS CHEMISTRY A, 3(20), 10949-10958.
Braunecker, W. A., Oosterhout, S. D., Owczarczyk, Z. R., Kopidakis, N., Ratcliff, E. L., Ginley, D. S., & Olson, D. C. (2014). Semi-random vs Well-Defined Alternating Donor-Acceptor Copolymers. ACS MACRO LETTERS, 3(7), 622-627.
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Cowan, S. R., Schulz, P., Giordano, A. J., Garcia, A., MacLeod, B. A., Marder, S. R., Kahn, A., Ginley, D. S., Ratcliff, E. L., & Olson, D. C. (2014). Chemically Controlled Reversible and Irreversible Extraction Barriers Via Stable Interface Modification of Zinc Oxide Electron Collection Layer in Polycarbazole-based Organic Solar Cells. ADVANCED FUNCTIONAL MATERIALS, 24(29), 4671-4680.
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Jenkins, J. L., Lee, P. A., Nebesny, K. W., & Ratcliff, E. L. (2014). Systematic electrochemical oxidative doping of P3HT to probe interfacial charge transfer across polymer-fullerene interfaces. JOURNAL OF MATERIALS CHEMISTRY A, 2(45), 19221-19231.
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Li, H., Ratcliff, E. L., Sigdel, A. K., Giordano, A. J., Marder, S. R., Berry, J. J., & Bredas, J. (2014). Modification of the Gallium-Doped Zinc Oxide Surface with Self-Assembled Monolayers of Phosphonic Acids: A Joint Theoretical and Experimental Study. ADVANCED FUNCTIONAL MATERIALS, 24(23), 3593-3603.
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Saavedra, S. S., McGrath, D. V., Armstrong, N. R., Ratcliff, E. L., Beam, B. M., Ratcliff, E. L., Ginger, D. S., Nordlund, D., Knesting, K. M., Gliboff, M., Oquendo, L. E., Polaske, N. W., & Lin, H. (2012). Electron Transfer Processes in Zinc Phthalocyanine-Phosphonic Acid Monolayers on ITO: Characterization of Orientation and Charge Transfer Kinetics By Waveguide Spectroelectrochemistry. J. Phys. Chem. Lett, 3, 1154-1158. doi:http://dx.doi.org/10.1021/jz3002426
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Gliboff, M., Sang, L., Knesting, K. M., Schalnat, M. C., Mudalige, A., Ratcliff, E. L., Li, H., Sigdel, A. K., Giordano, A. J., Berry, J. J., Nordlund, D., Seidler, G. T., Bredas, J., Marder, S. R., Pemberton, J. E., & Ginger, D. S. (2013). Orientation of Phenylphosphonic Acid Self-Assembled Monolayers on a Transparent Conductive Oxide: A Combined NEXAFS, PM-IRRAS, and DFT Study. LANGMUIR, 29(7), 2166-2174.
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Matz, D. L., Ratcliff, E. L., Meyer, J., Kahn, A., & Pemberton, J. E. (2013). Deciphering the Metal-C-60 Interface in Optoelectronic Devices: Evidence for C-60 Reduction by Vapor Deposited Al. ACS APPLIED MATERIALS & INTERFACES, 5(13), 6001-6008.
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Ndione, P. F., Garcia, A., Widjonarko, N. E., Sigdel, A. K., Steirer, K. X., Olson, D. C., Parilla, P. A., Ginley, D. S., Armstong, N. R., Richards, R. E., Ratcliff, E. L., & Berry, J. J. (2013). Highly-Tunable Nickel Cobalt Oxide as a Low-Temperature P-Type Contact in Organic Photovoltaic Devices. ADVANCED ENERGY MATERIALS, 3(4), 524-531.
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Ratcliff, E. L., Bakus, R. C., Welch, G. C., van der Poll, T. S., Garcia, A., Cowan, S. R., MacLeod, B. A., Ginley, D. S., Bazan, G. C., & Olson, D. C. (2013). Formation of interfacial traps upon surface protonation in small molecule solution processed bulk heterojunctions probed by photoelectron spectroscopy. JOURNAL OF MATERIALS CHEMISTRY C, 1(39), 6223-6234.
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Ratcliff, E. L., Garcia, A., Paniagua, S. A., Cowan, S. R., Giordano, A. J., Ginley, D. S., Marder, S. R., Berry, J. J., & Olson, D. C. (2013). Investigating the Influence of Interfacial Contact Properties on Open Circuit Voltages in Organic Photovoltaic Performance: Work Function Versus Selectivity. ADVANCED ENERGY MATERIALS, 3(5), 647-656.
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Steirer, K. X., MacDonald, G. A., Olthof, S., Gantz, J., Ratcliff, E. L., Kahn, A., & Armstrong, N. R. (2013). Energy Level Alignment and Morphology of Ag and Au Nanoparticle Recombination Contacts in Tandem Planar Heterojunction Solar Cells. JOURNAL OF PHYSICAL CHEMISTRY C, 117(43), 22331-22340.
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Garcia, A., Welch, G. C., Ratcliff, E. L., Ginley, D. S., Bazan, G. C., & Olson, D. C. (2012). Improvement of Interfacial Contacts for New Small-Molecule Bulk-Heterojunction Organic Photovoltaics. ADVANCED MATERIALS, 24(39), 5368-5373.
Lin, H., Polaske, N. W., Oquendo, L. E., Gliboff, M., Knesting, K. M., Nordlund, D., Ginger, D. S., Ratcliff, E. L., Beam, B. M., Armstrong, N. R., McGrath, D. V., & Saavedra, S. S. (2012). Electron-Transfer Processes in Zinc Phthalocyanine Phosphonic Acid Monolayers on ITO: Characterization of Orientation and Charge-Transfer Kinetics by Waveguide Spectroelectrochemistry. JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 3(9), 1154-1158.
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MacLeod, B. A., Horwitz, N. E., Ratcliff, E. L., Jenkins, J. L., Armstrong, N. R., Giordano, A. J., Hotchkiss, P. J., Marder, S. R., Campbell, C. T., & Ginger, D. S. (2012). Built-In Potential in Conjugated Polymer Diodes with Changing Anode Work Function: Interfacial States and Deviation from the Schottky-Mott Limit. JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 3(9), 1202-1207.
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Ratcliff, E. L., Meyer, J., Steirer, K. X., Armstrong, N. R., Olson, D., & Kahn, A. (2012). Energy level alignment in PCDTBT:PC70BM solar cells: Solution processed NiOx for improved hole collection and efficiency. ORGANIC ELECTRONICS, 13(5), 744-749.
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Ratcliff, E. L., Sigdel, A. K., Macech, M. R., Nebesny, K., Lee, P. A., Ginley, D. S., Armstrong, N. R., & Berry, J. J. (2012). Surface composition, work function, and electrochemical characteristics of gallium-doped zinc oxide. THIN SOLID FILMS, 520(17), 5652-5663.
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Widjonarko, N. E., Ratcliff, E. L., Perkins, C. L., Sigdel, A. K., Zakutayev, A., Ndione, P. F., Gillaspie, D. T., Ginley, D. S., Olson, D. C., & Berry, J. J. (2012). Sputtered nickel oxide thin film for efficient hole transport layer in polymer-fullerene bulk-heterojunction organic solar cell. THIN SOLID FILMS, 520(10), 3813-3818.
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Polaske, N. W., Lin, H., Tang, A., Mayukh, M., Oquendo, L. E., Green, J. T., Ratcliff, E. L., Armstrong, N. R., Saavedra, S. S., & McGrath, D. V. (2011). Phosphonic Acid Functionalized Asymmetric Phthalocyanines: Synthesis, Modification of Indium Tin Oxide, and Charge Transfer. LANGMUIR, 27(24), 14900-14909.
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Ratcliff, E. L., Meyer, J., Steirer, K. X., Garcia, A., Berry, J. J., Ginley, D. S., Olson, D. C., Kahn, A., & Armstrong, N. R. (2011). Evidence for near-Surface NiOOH Species in Solution-Processed NiOx Selective Interlayer Materials: Impact on Energetics and the Performance of Polymer Bulk Heterojunction Photovoltaics. CHEMISTRY OF MATERIALS, 23(22), 4988-5000.
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Ratcliff, E. L., Zacher, B., & Armstrong, N. R. (2011). Selective Inter layers and Contacts in Organic Photovoltaic Cells. JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 2(11), 1337-1350.
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Steirer, K. X., Ndione, P. F., Widjonarko, N. E., Lloyd, M. T., Meyer, J., Ratcliff, E. L., Kahn, A., Armstrong, N. R., Curtis, C. J., Ginley, D. S., Berry, J. J., & Olson, D. C. (2011). Enhanced Efficiency in Plastic Solar Cells via Energy Matched Solution Processed NiOx Interlayers. ADVANCED ENERGY MATERIALS, 1(5), 813-820.
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Kim, B. Y., Ratcliff, E. L., Armstrong, N. R., Kowalewski, T., & Pyun, J. (2010). Ferrocene Functional Polymer Brushes on Indium Tin Oxide via Surface-Initiated Atom Transfer Radical Polymerization. LANGMUIR, 26(3), 2083-2092.
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Ratcliff, E. L., Lee, P. A., & Armstrong, N. R. (2010). Work function control of hole-selective polymer/ITO anode contacts: an electrochemical doping study. JOURNAL OF MATERIALS CHEMISTRY, 20(13), 2672-2679.
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Ratcliff, E. L., Veneman, P. A., Simmonds, A., Zacher, B., Huebner, D., Saavedra, S. S., & Armstrong, N. R. (2010). A Planar, Chip-Based, Dual-Beam Refractometer Using an Integrated Organic Light-Emitting Diode (OLED) Light Source and Organic Photovoltaic (OPV) Detectors. ANALYTICAL CHEMISTRY, 82(7), 2734-2742.
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Keng, P. Y., Shim, I., Kim, B. Y., Sahoo, R., Veneman, P. E., Armstrong, N. R., Yoo, H., Pemberton, J. E., Bull, M. M., Griebel, J. J., Ratcliff, E. L., Nebesny, K. W., Pyun, D., Keng, P. Y., Shim, I., Kim, B. Y., Sahoo, R., Veneman, P. E., Armstrong, N. R., , Yoo, H., et al. (2009). Colloidal Polymerization of Polymer Coated Ferromagnetic Nanoparticles into Cobalt Oxide Nanowires. ACS Nano, 3, 3143-3157.
Ratcliff, E. L., Jenkins, J. L., Nebesny, K., & Armstrong, N. R. (2008). Electrodeposited, "textured" poly(3-hexyl-thiophene) (e-P3HT) films for photovoltaic applications. CHEMISTRY OF MATERIALS, 20(18), 5796-5806.
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Ratcliff, E. L., & Hillier, A. C. (2007). Directed Electrodeposition of polymer films using spatially controllable electric field gradients. LANGMUIR, 23(19), 9905-9910.
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Proceedings Publications
Ratcliff, E. L., Garcia, A., Cowan, S. R., Meyer, J., Steirer, K. X., Paniagua, S. A., Giordano, A., Marder, S., Armstrong, N. R., Kahn, A., Ginley, D., Olson, D. C., & , . (2012). Understanding Energy Level Alignment in PCDTBT:PC70BM Solar Cells. In 2012 38TH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC), 3377-3379.
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Jenkins, J. L., Ratcliff, E. L., Shallcross, R. C., Head, J. L., Armstrong, N. R., & Tsakalakos, L. (2008). Photovoltaic devices created from electrodeposited, "nano-textured" poly(thiophene) films. In NANOSCALE PHOTONIC AND CELL TECHNOLOGIES FOR PHOTOVOLTAICS, 7047.
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Reviews
Armstrong, N. R., Veneman, P. A., Ratcliff, E., Placencia, D., & Brumbach, M. (2009. Oxide Contacts in Organic Photovoltaics: Characterization and Control of Near-Surface Composition in Indium-Tin Oxide (ITO) Electrodes(pp 1748-1757).
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Armstrong, N. R., Wang, W., Alloway, D. M., Placencia, D., Ratcliff, E., & Brumbach, M. (2009. Organic/Organic' Heterojunctions: Organic Light Emitting Diodes and Organic Photovoltaic Devices(pp 717-731).
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Keng, P. Y., Kim, B. Y., Shim, I., Sahoo, R., Veneman, P. E., Armstrong, N. R., Yoo, H., Pemberton, J. E., Bull, M. M., Griebel, J. J., Ratcliff, E. L., Nebesny, K. G., & Pyun, J. (2009. Colloidal Polymerization of Polymer-Coated Ferromagnetic Nanoparticles into Cobalt Oxide Nanowires(pp 3143-3157).
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Others
Gliboff, M., Sang, L., Knesting, K. M., Schalnat, M. C., Mudalige, A., Ratcliff, E. L., Li, H., Sigdel, A. K., Giordano, A. J., Berry, J. J., Nordlund, D., Seidler, G. T., Bredas, J., Marder, S. R., Pemberton, J. E., & Ginger, D. S. (2013, MAR 26). Orientation of Phenylphosphonic Acid Self-Assembled Mono layers on a Transparent Conductive Oxide: A Combined NEXAFS, PM-IRRAS, and DFT Study (vol 29, pg 2166, 2013). LANGMUIR.

 

https://profiles.arizona.edu/person/ratcliff