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2012

• "Analysis of voltage and temperature dependent photocurrent collection in p3ht/pcbm solar cells," Bakhtyar Ali, Roy Murray, Steven S. Hegedus, and S. Ismat Shah, J. Appl. Phys. 112, 114514 (2012).

• "Effect of surface carbon on the hydrogen evolution reactivity of tungsten carbide (WC) and Pt-modified WC electrocatalysts," Yannick C. Kimmel, Daniel V. Esposito, Robert W. Birkmire, Jingguang G. Chen, International Journal of Hydrogen Energy, in-press (2012).

• "Electron drift-mobility measurements in polycrystalline CuIn1-xGaxSe2 solar cells," S. A. Dinca, E. A. Schiff, W. N. Shafarman, B. Egaas, R. Noufi, and D. L. Young, Applied Phys Letters, 100, 103901 (2012).

• "Three-step H2Se/Ar/H2S reaction of Cu-In-Ga precursors for controlled composition and adhesion of Cu(In,Ga)(Se,S)2 thin films," Kihwan Kim, Gregory M. Hanket, Trang Huynh, William N.Shafarman, J. Applied Phys, 111, 083710 (2012).

• "Photoelectrochemical reforming of glucose for hydrogen production using a WO3-based tandem cell device," Daniel V. Esposito, Robert V. Forest, Yuancheng Chang, Nicolas Gaillard, Brian E. McCandless, Shuyu Hou, Kelvin H. Lee, Robert W. Birkmire, Jingguang G. Chen, Energy Environ. Sci., 5, 9091-9099 (2012).

• "Impact of back surface patterning process on FF in IBC-SHJ solar cell," Lulu Zhang, Brent Shu, Robert Birkmire, Steve Hegedus, Ujjwal Das, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

• "Design of anti-reflection coating for surface textured interdigitated back contact silicon hetero-junction solar cell," Brent Shu, Ujjwal Das, Lei Chen, Lulu Zhang, Steven Hegedus, Robert Birkmire, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

• "Characterization and modeling of low temperature surface passivation for interdigitated back contact silicon hetero-junction solar cell," Brent Shu, Ujjwal Das, Steven Hegedus, Robert Birkmire, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

• "The effects of device geometry and TCO/buffer layers on damp heat accelerated lifetime testing of Cu(In,Ga)Se2 solar cells," Chris Thompson, Steve Hegedus, Peter Carcia, R. Scott McLean, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

• "Effect of annealing atmosphere and temperature on the properties of Cd2SnO4 thin films," Tiejun Meng, Brian E. McCandless, Wayne A. Buchanan, Robert W. Birkmire, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

• "Control of Ga profiles in (AgCu)(InGa)Se2 absorber layers deposited on polyimide substrates," Gregory M. Hanket, Christopher P. Thompson, Erten Eser, William N. Shafarman, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

• "Three-step H2Se/Ar/H2S reaction of metal precursors for large area Cu(In,Ga)(Se,S)2 with uniform Ga distribution," Kihwan Kim, Evan L. Kimberly, Andrew Damiani, Gregory M. Hanket, William N. Shafarman, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

• "High efficiency ultra-thin Cu(In,Ga)(Se,S)2 solar cells by three-step H2Se/Ar/H2S reaction of Cu-In-Ga metal precursor," Kihwan Kim, Hyeonwook Park, Woo Kyoung Kim, Gregory M. Hanket, William N. Shafarman, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

• "Characterization of (AgCu)(InGa)Se2 absorber layer fabricated by selenization process from metal precursor," Yuki Tauchi, Kihwan Kim, Hyeonwook Park, William Shafarman, Proc. 38th IEEE PVSC, Austin, TX, June 3-6, 2012.

2011

• "Structural characterization of the (AgCu)(InGa)Se2 thin film alloy system for solar cells," J.H. Boyle, B.E. McCandless, G.M. Hanket, W.N. Shafarman, Thin Solid Films (2011).

• "Improved FF in p-Si heterojunction solar cells due to optimized ITO/emitter contact," Zeynep Eygi, Ujjwal Das, Steven Hegedus, Robert Birkmire, Proc. 37th IEEE PVSC, Seattle WA, June 20-24, 2011.

• "Surface Characterization of (AgCu)(InGa)Se2 Thin Films for Solar Cells," Hamed Simchi, Brian McCandless, William Shafarman, Kihwan Kim, Jonathan Boyle, and Robert Birkmire, Proc. 37th IEEE PVSC, Seattle WA, June 20-24, 2011.

• "Cu-In-Ga Metal Precursors Sputter Deposited from a Single Ternary Target for Cu(lnGa)(SeS)2 Film Formation," Trang Huynh, Wayne Buchanan, Kihwan Kim, Brian McCandless, William Shafarman, Robert Birkmire, Proc. 37th IEEE PVSC, Seattle WA, June 20-24, 2011.

• "Interdigitated back contact silicon hetero-junction solar cells: the effect of doped layer defect levels on fill factor using two-dimensional simulations," John Allen, Brent Shu, Ujjwal Das, Steven Hegedus, Proc. 37th IEEE PVSC, Seattle WA, June 20-24, 2011.

• "Hydrogen production from photo-driven electrolysis of biomass-derived oxygenates: A case study on methanol using Pt-modified WO3 thin film electrodes," Daniel V. Esposito, Jingguang G. Chen, Robert W. Birkmire, Yuancheng Chang, Nicolas Gaillard, International Journal of Hydrogen Energy 36, 9632-9644 (2011)

• "Atomic layer deposition of pt on tungsten monocarbide (WC) for the oxygen reduction reaction," Irene J. Hsu, Danielle A. Hansgen, Brian E. McCandless, Brian G. Willis, Jingguang Chen, J. Phys. Chem. 115, 3709-3715 (2011).

• "Ga homogenization by simultaneous H2Se/H2S reaction of Cu-Ga-In precursor," Woo Kyoung Kim, Gregory M. Hanket, William N. Shafarman, J. Sol. Mat. 95, 235-238 (2011).

• "Metastable properties of Cu(In1-xGax)Se2 with and without sodium," Peter T. Erslev, William N. Shafarman, J. David Cohen, Applied Physics Letters 98, 062105 (2011).

2010

• "Cu(In,Ga)Se2 Film Formation From Selenization of Mixed Metal/Metal-selenide Precursors," Rui Kamada, William N. Shafarman and Robert W. Birkmire, Solar Energy Materials & Solar Cells 94, 451 (2010).

• "A Comparative Study of Photoconductivity and Carrier Transport in a-Si:H p-i-n Solar Cells with Different Back Contacts," R. Kaplan, B. Kaplan, S.S. Hegedus, Solid-State Electronics 54, 22 (2010).

• "Device Characterization of (AgCu)(InGa)Se2 Solar Cells," William Shafarman, Christopher Thompson, Jonathan Boyle, Gregory Hanket, Peter Erslev and J. David Cohen, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Commercial-Scale Sources for the Evaporation of Elemental Cu, Ga, and In: Modeling, Design and Validation," Gregory M. Hanket, Robert W. Birkmire, Shannon Fields, and Erten Eser, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Wide-bandgap (AgCu)(InGa)Se2 Absorber Layers Deposited by Three-stage Co-evaporation, Gregory Hanket, Jonathan H. Boyle, William N. Shafarman, and Glenn Teeter, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Alternative Approaches for Low Temperature Front Surface Passivation of Interdigitated Back Contact Silicon Heterojunction Solar Cell," Brent Shu, Ujjwal Das, Jesse Appel, Brian McCandless, Steven Hegedus and Robert Birkmire, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Encapsulation of Cu(InGa)Se2 Solar Cells with ALD Al2O3 Flexible Thin-film Moisture Barrier; Stability Under 1000 Hour Damp Heat and UV Exposure," Steven S. Hegedus, P.F. Carcia, R.S. McLean, Bradley Culver, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Quantitative Analysis and Extraction of Cell Parameters from Interconnected Thin-Film Solar Modules Through LBIC-voltage Sweeps," Jonathan M. Frey, Steven S. Hegedus, and Christopher P. Thompson, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Investigation of Hetero-interface and Junction Properties in Silicon Heterojunction Solar Cells," Ujjwal Das Steven Hegedus, Lulu Zhang, Jesse Appel, Jim Rand, and Robert Birkmire, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Cu(InGa)Se2 Photovoltaics on Insulated Stainless Steel Web Substrate," Erten Eser, Shannon Fields, Woo K. Kim, Elizabeth McQuiston, Kihwan Kim, and William N. Shafarman, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Effect of Junction Interface Modification of Silicon Heterojunction Solar Cells," Jesse Appel, Lulu Zhang, Ujjwal Das, Steven Hegedus, Swapna Mudigonda, Robert Birkmire, Jim Rand, Proc. 35th IEEE PVSC, Waikiki, Hawaii, June 21-25, 2010.

• "Optimization of Interdigitated Back Contact Silicon Heterojunction Solar Cells: Tailoring Hetero-interface Band Structures While Maintaining Surface Passivation," Meijun Lu, Ujjwal Das, Stuart Bowden, Steven Hegedus and Robert Birkmire, Prog. Photovolt. Res. Appl. DOI: 10.1002/pip. 1032 (2010).

• "Commercial-Scale Deposition of Cu(InGa)Se2 Thin Films by Thermal Evaporation," Gregory M. Hanket, Future Photovoltaics, Sept (2010).

• "Aluminum-induced crystallization of amorphous silicon films deposited by hot wire chemical vapor deposition on glass substrates," Ozgenc Ebil, Roger Aparicio, Robert Birkmire, Thin Solid Films 510, 178 (2010).

• "Encapsulation of Cu(InGa)Se2 Solar Cell with Al2O3 Thin-film Moisture Barrier rown by Atomic Layer Deposition," P.F. Carcia, R.S. McLean, Steven Hegedus, Solar Energy Materials & Solar Cells 94, 2375-2378 (2010).

• "Thin-Film Solar Cells and Modules," Robert W. Birkmire, Solar Cells and Their Applications, Second Edition book (Wiley Series in Microwave and Optical Engineering), Chapter 6, 137-157 (2010).

• "CdTe thin film technology: Leading thin film PV into the future," Robert W. Birkmire, Brian E. McCandless, Current Opinion in Solid State and Materials Science 14, 139-142 (2010).

• "Low-cost hydrogen-evolution catalysts based on monolayer platinum on tungsten monocarbide substrates," Daniel Esposito, Sean T. Hunt, Alan L. Stottlemyer, Kevin D. Dobson, Brian E. McCandless, Robert W. Birkmire, Jingguang G. Chen, Angew. Chem. Int. Ed. 49, 9859-9862 (2010).

• "Electrochemical stability of tungsten and tungsten monocarbide (WC) Over Wide pH and Potential Ranges," Mark C. Weidman, Daniel Esposito, Irene J. Hsu, Jingguang Chen, J. Electrochem. Soc. 157 (12), F179-F188 (2010).

2009

• "The Influence of Na on Metastable Defect Kinetics in CIGS Materials," Peter T. Erslev, Jin Woo Lee, William N. Shafarman, J. David Cohen, J. Thin Film Solids 517, 2277-2381 (2009).

• "Optimization of Interdigitation Parameters for Back Contact Si Heterojunction Solar Cells,"O. Jani, U. Das, S. Herasimenka, M. Lu, D. Xu, S. Bowden, S. Hegedus, R. Birkmire, PVSEC18 (2009).

• "Designing Rear Surface for Carrier Transport in Back Contact Si Heterojunction Solar Cells," U. Das, M. Lu, D. Xu, O. Jani, S. Bowden, S. Hegedus, R. Birkmire, PVSEC18 (2009).

• "In-situ Post-deposition Thermal Annealing of Co-evaporated Cu(InGa)Se2 Thin Films Deposited at Low Temperatures," James D. Wilson, Brian E. McCandless, Robert W. Birkmire, William N. Shafarman, Proc. 34th IEEE PVSC, Philadelphia, PA, June 8-12, 2009.

• "Characterization and Device Performance of (AgCu)(InGa)Se2 Absorber Layers," Gregory M. Hanket, Jonathan H. Boyle, and William N. Shafarman, Proc. 34th IEEE PVSC, Philadelphia, PA, June 8-12, 2009.

• "Processing of Cu(In,Ga)Se2 Solar Cells from Electrodeposited Precursors," Kevin D. Dobson and Robert W. Birkmire, Proc. 34th IEEE PVSC, Philadelphia, PA, June 8-12, 2009.

• "Ga Distribution and Adhesion Issues in Selenization of Metallic Cu-Ga-In Precurcors," Woo Kyoung Kim, Gregory M. Hanket and William N. Shafarman, Proc. 34th IEEE PVSC, Philadelphia, PA, June 8-12, 2009.

• "Optimization of Interdigitated Back Contact Silicon Heterojunction Solar Cells by Two-dimensional Numerical Simulation," Meijun Lu, Ujjwal Das, Stuart Bowden, Steven Hegedus and Robert Birkmire, Proc. 34th IEEE PVSC, Philadelphia, PA, June 8-12, 2009.

• "Low Temperature Front Surface Passivation of Interdigitated Back Contact Silicon Heterojunction Solar Cell," Brent Shu, Ujjwal Das, Omkar Jani, Steven Hegedus, and Robert Birkmire, Proc. 34th IEEE PVSC, Philadelphia, PA, June 8-12, 2009.

• "Optical and Quantum Efficiency Analysis of (Ag,Cu)(In,Ga)Se2 Absorber Layers," Jonathan Boyle, Gregory Hanket and William Shafarman, Proc. 34th IEEE PVSC, Philadelphia, PA, June 8-12, 2009.

• "Roll-to-Roll Deposition of a Semiconductor Film on a Flexible Substrate for Photovoltaics: Conception to Reality," Gregory M. Hanket, Robert W. Birkmire, Scott C. Jackson and Richard E. Rocheleau, Ind. Eng. Chem. Res. 48, 5923-5933 (2009).

• "Scaleup of Cu(InGa)Se2 Thin Film Coevaporative Physical Vapor Deposition Process, 1. Evaporation Source Model Development," Kapil Mukati, Babatunde A. Ogunnaike, Erten Eser, Shannon Fields, and Robert W. Birkmire, Ind. Eng. Chem. Res. 48, 5975-5991 (2009).

• "Understanding Defect-related Issues Limiting Efficiency of CIGS Solar Cells," Matgorzata Igalson, Pawel Zabierowski, Daniel Przado, Aleksander Urganiak, Marika Edoff, William N. Shafarman, Solar Energy Materials & Solar Cells 93, 1290-1295 (2009).

• "Pin Double-heterojunction Thin-film Solar Cell p-layer Assessment," J.A. Spies, R. Schafer, J.F. Wager, P. Hersh, H.A.S. Platt, D.A. Keszler, G. Schneider, R. Kykyneshi, J. Tate, X. Lu, A.D. Compaan, W.N. Shafarman, Solar Energy Materials & Solar Cells 93, 1296-1308 (2009).

• "Characterizing the Effects of Silver Alloying in Chalcopyrite CIGS Solar Cells with Junction Capacitance Methods," Peter T. Erslev, Gregory M. Hanket, William N. Shafarman, and J. David Cohen, Mater. Res. Soc. Symp. 1165, 1165-M01-07 (2009).

• "A New Photoelectrochemical Test Cell and Its Use for a Combined Two-electrode and Three-electrode Approach to Cell Testing," Daniel V. Esposito, Ouloide Y. Goue, Kevin D. Dobson, Brian E. McCandless, Jingguang G. Chen, and Robert W. Birkmire, Review of Scientific Instruments 80, 125107 (2009).

• "A Comparative Study of Tungsten Monocarbide and Platinum as Counterelectrodes in Polysulfide-Based Photoelectrochemical Solar Cells," D.V. Esposito, K.D. Dobson, B.E. McCandless, R.W. Birkmire and J.G. Chen, J. Electrochem. Soc. 156, B962-B969 (2009).

• "Hole drift mobility measurements in polycrystalline CuIn1-xGaxSe2," S. A. Dinca, E. A Schiff, B. Egaas, R. Noufi, D. L. Young, W. N. Shafarman, Physical Review B 80, 235201 (2009).

2008

• "Electrodeposition of CuInSe2 Absorber Layers from pH Buffered and Non-buffered Sulfate-based Solutions," C. Sene, M. Estela Calixto, Kevin D. Dobson, Robert W. Birkmire, Thin Solid Films 516, 2188 (2008). http://dx.doi.org/10.1016/j.tsf.2007.07.142

• "Surface Passivation and Heterojunction Cells on Si (100) and (111) Wafers Using dc and rf Plasma Deposited Si:H Thin Films," U.K. Das, M.Z. Burrows, M. Lu, S. Bowden and R.W. Birkmire, Appl. Phys. Lett. 92, 063504 (2008). http://link.aip.org/link/?APL/92/063504

• "Electronic Level Alignment at the Deeply Buried Absorber/Mo Interface in Chalcopyrite-based Thin Film Solar Cells," M. Bar, S. Nichiwaki, L. Weinhardt, S. Pookpanratana, W.N. Shafarman and C. Heske, Appl. Phys. Lett. 83, 042110 (2008).

• "Chemical Structures of the Cu(In,Ga)Se2/Mo Interfaces," M. Bar, L. Weinhardt, C. Heske, S. Nishiwaki and W.N. Shafarman, Phys. Rev. B 78, 075404 (2008).

• "Composition Control of Cu(InGa)(SeS)2 Deposited by Elemental Coevaporation," Shiro Nishiwaki and William N. Shafarman, J. Appl. Phys. 104, 034912 (2008).

• "Effect of Texturing and Surface Preparation on Lifetime and Cell Performance in Heterojunction Silicon Solar Cells," Matthew Edwards, Stuart Bowden, Ujjwal Das, Michael Burrows, Solar Energy Materials & Solar Cells 92, 1373 (2008).

• "Improved Passivation of a-Si:H/c-Si Interfaces Through Film Restructuring," M.Z. Burrows, U.K. Das, S. Bowden, S.S. Hegedus, R.L. Opila, and R.W. Birkmire, Mat. Res. Soc. Symp. Proc. 1066, 1066-A02-05 (2008).

• "Role of Hydrogen Bonding Environment in a-Si:H Films for c-Si Surface Passivation," M.Z. Burrows, U.K. Das, R.L. Opila, S. DeWolf, R.W. Birkmire, J. Vac. Sci. Technol. A26(4), 683 (2008).

• "Pathways to Improved Performance and Processing of CdTe and CuInSe2 Based Modules," Robert Birkmire, Proc. 33rd IEEE PVSC, (2008).

• "Stability of Amorphous-Crystalline Silicon Heterojunctions," Stuart Bowden, Ujjwal Das, Robert Birkmire, Proc. 33rd IEEE PVSC, (2008).

• "Rear Surface Passivation of Interdigitated Back Contact Silicon Heterojunction Solar Cell and 2D Simulation Study," Meijun Lu, Ujjwal Das, Stuart Bowden, Robert Birkmire. Proc. 33rd IEEE PVSC, (2008).

• "Effect of Reaction Temperature on Cu(InGa)(SeS)2 Formation by Sequential H2Se/H2S Precursor Reaction Processes," Gregory Hanket, Rui Kamada, William Shafarman, Woo Kyoung Kim, Proc. 33rd IEEE PVSC, (2008).

• "Cu(InGa)Se2 Film Formation from Selenization of Mixed Metal./Metal-selenide Precursors," Rui Kamada, William Shafarman, Robert Birkmire, Proc. 33rd IEEE PVSC, (2008).

• "High Throughput Processing CdTe/CdS Solar Cells with Thin Absorber Layers," Brian McCandless and Wayne Buchanan, Proc. 33rd IEEE PVSC, (2008).

• "Cross-Section Potential Analysis of CdTe/CdS Solar Cells by Kelvin Probe Force Microscopy," Brian McCandless and Sergey Rykov, Proc. 33rd IEEE PVSC, (2008).

• "Control of Composition in Co-evaporated Cu(InGa)(SeS)2 Thin Films," Shiro Nishiwaki, Greg Hanket, Robert Birkmire and William Shafarman, Proc. 33rd IEEE PVSC, (2008).

• "Temperature Dependence of VOC in CdTe and Cu(InGa)(SeS)2-based Solar Cells," Christopher Thompson, Steven Hegedus, William Shafarman and Darshini Desai, Proc. 33rd IEEE PVSC, (2008).

• "In-situ Annealing of Cu(InGa)Se2 Films Grown by Elemental Co-evaporation," James Wilson, Robert Birkmire and William Shafarman, Proc. 33rd IEEE PVSC, (2008).

• "Properties of Encapsulated CIGS Cells in 85ºC/85%RH," Larry C. Olsen, Mark E. Gross and Sambhu N. Kundu, Pacific Northwest National Laboratory, Richland, WA 99354; William N. Shafarman, Institute of Energy Conversion,University of Delaware, Newark, DE 19716, Proc. 33rd IEEE PVSC, (2008).

• "Band Gap Energy of Chalcopyrite Thin Film Solar Cell Absorbers Determined by Soft X-ray Emission and Absorption Spectroscopy," M. Bar, L. Weinhardt, S. Pookpanratana and C. Heske Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Pkwy, Las Vegas, NV 89154-4003 USA; S. Nishiwaki and W.N. Shafarman, Institute of Energy Conversion (IEC), University of Delaware, 451 Wyoming Rd., Newark, DE 19716, USA; O. Fuchs and M. Blum Experimentelle Physik II, Universitat Wurzburg, Am Hubland, D97074 Wurzburg, Germany; W. Yang and J.D. Delinnger, Advanced Light Source (ALS), Lawrence Berkeley National Laboratory, 1 Cyclotron Rd.., Berkeley, CA 94720, USA, Proc. 33rd IEEE PVSC, (2008).

• "Characterization of 19.9%-Efficient CIGS Absorbers," I. Repins, M. Contreras, M. Romero, Y. Yan, W. Metzger, J. Li, S. Johnston, B. Egaas, C. DeHart, and J. Scharf, National Renewable Energy Laboratory, B.E. McCandless, Institute of Energy Conversion, and R. Noufi, Solopower, Proc. 33rd IEEE PVSC, (2008), NREL/CP-520-42639.

• "Structure and Optoelectronics of Electrodeposited Cadmium Ditelluride (CdTe2)," Jean Rousset, Par Olsson, Brian McCandless and Daniel Lincot, American Chemical Society, 6550 (2008).

• "Development of CuInSe2 Nanocrystal and Nanoring Inks for Low-Cost Solar Cells," Qiije Guo, Suk Jun Kim, Mahaprasad Kar, William N. Shafarman, Robert W. Birkmire, Eric A Stach, Rakesh Agrawal, and Hugh W. Hillhouse, Nano Letters 8 (9), 2982-2987 (2008).

• "Progress Towards High Efficiency All Back Contact c-Si Heterojunction Solar Cells," U. Das, S. Bowden, M. Lu, M. Burrows, D. Xu, O. Jani, S. Hegedus, R. Birkmire, Proc. 18th Workshop on Crystalline Silicon Solar Cells, 70 (2008).

• "Depth-resolved band gap in Cu(In,Ga)(S,Se)2 thin films," M. Bar, S. Nishiwaki, L. Weinhardt, S. Pookpanratana, O. Fuchs, M. Blum, W. Yang, J. D. Denlinger, W. N. Shafarman, C. Heske, Applied Physics Letters 93, 244103 (2008).

2007

• "Contact Wetting Angle as a Characterization Technique for Processing CdTe/CdS Solar Cells," M.S. Angelo, B.E. McCandless, R.W. Birkmire, R.A. Rykov and J.G. Chen, Prog. Photovolt: Res. Appl. 15, 93 (2007).

• "Interdigitated back contact silicon heterojunction solar cell and the effect of front surface passivation," Meijun Lu, Stuart Bowden, Ujjwal Das, Robert Birkmire, Appl. Phys. Lett. 91, 063407 (2007) http://link.aip.org/link/?APL/91/063507

• "Composition Control in the Deposition of Cu(InGa)(SeS)2 Thin Films," William Shafarman, Gregory Hanket, and Shiro Nishiwaki, Mater. Res. Soc. Symp. Proc. 1012, 1012-Y02-01, (2007).

• "Understanding Metastable Defect Creation in CIGS by Detailed Device Modeling and Measurements on Bifacial Solar Cells," JinWoo Lee, David Berney Needleman,William N. Shafarman, and J. David Cohen, Mater. Res. Soc. Symp. Proc. 1012, 1012-Y04-02, (2007).

• "Energetics of Both Minority and Majority Carrier Transitions through Deep Defects in Wide Bandgap Pentenary Cu(In,Ga)(Se,S)2 Thin Film Solar Cells." Adam Halverson, Shiro Nishiwaki, William Shafarman, and J. David Cohen, Mater. Res. Soc. Symp. Proc.1012, 1012-Y04-04, (2007).

• "Electronic Defects and Device Performance in CuGaSe2 Solar Cells," J. Jedediah Rembold, Todd W. Curtis, Jennifer T. Heath, David L. Young, Steve W. Johnston, and William N. Shafarman, Mater. Res. Soc. Symp. Proc.1012, 1012-Y12-27, (2007).

• "Study of the Electronic Properties of Matched Na-Containing and Reduced-Na CuInGaSe2 Samples Using Junction Capacitance Methods," Peter T. Erslev, Adam Halverson, William Shafarman, and J. David Cohen, Mater. Res. Soc. Symp. Proc. 1012, 1012-Y12-30, (2007).

• "Hydrofluoric Acid Treatment of Amorphous Silicon Films for Photovoltaic Processing," M. Burrows, U. Das, M. Lu, S. Bowden, R. Opila, and R. Birkmire, Mater. Res. Soc. Symp. Proc. 989, 0989-A18-06 (2007).

• "Interdigitated Back Contact Silicon Heterojunction (IBC-SHJ) Solar Cell," Meijun Lu, Stuart Bowden, Ujjwal Das, Michael Burrows, and Robert Birkmire, Mater. Res. Soc. Symp. Proc. 989, 0989-A24-05 (2007).

• "Incongruent Reaction of Cu-(InGa) Intermetallic Precursors in H2Se and H2S," G.M. Hanket, W.N. Shafarman, B.E. McCandless and R.W. Birkmire, J. Appl. Phys. 102, 074823 (2007). http://link.aip.org/link/?JAP/102/074922

• "Voltage Dependent Photocurrent Collection in CdTe/CdS Solar Cells," Steven Hegedus, Darshini Desai and Chris Thompson, Prog. Photovolt: Res. Appl. 15, 587 (2007).

• "Determining lifetime silicon blocks and wafers with accurate expressions for carrier density," Stuart Bowden, Ronald A. Sinton, J. Appl. Phys. 102, 124501 (2007).

• "Evaluation of HF Treated Amorphous Silicon for Photoemission Determined Electronic Levels," M. Burrow, R. Opila, K. Kemirkan, M. Lu, U. Das, S. Bowden and R. Birkmire, Proc. 22nd Euro. PV Solar Energy Conf., 1290 (2007).

• "Surface Passivation Quality and Structure of Thin Si:H Layers on N-type Crystalline Si (100) and (111) Wafers," U.K. Das, M.Burrows, M. Lu, S. Bowden, and R.W. Birkmire, Proc. 22nd Euro. PV Solar Energy Conf., 1290 (2007).

• "A-Si/c-Si Heterojunction for Interdigitated Back Contact Solar Cell," Meijun Lu, Stuart Bowden, Ujjwal Das, and Robert Birkmire, Proc. 22nd Euro. PV Solar Energy Conf., 1290 (2007).

• "Milestones Toward 50% Efficient Solar Cell Modules," Allen Barnett, Douglas Kirkpatrick, Christiana Honsberg, Duncan Moore, Mark Wanlass, Keith Emery, Richard Schwartz, Dave Carlson, Stuart Bowden, Dan Aiken, Allen Gray, Sarah Kurtz, Larry Kazmerski, Tom Moriarty, Myles Steiner, Jeffrey Gray, Tom Davenport, Roger Buelow, Laszio Takacs, Markis Shatz, John Bortz, Omkar Jani, Keith Goossen, Fouad Kiamilev, Alan Doolittle, Ian Ferguson, Blair Unger, Grag Schmidt, Eric Christensen, David Salzman, Proc. 22nd Euro. PV Solar Energy Conf., 1290 (2007).

• "Texturing for Heterojunction Silicon Solar Cells," Matthew B. Edwards, Stuart B. Bowden, and Ujjwal K. Das, Proc. 22nd Euro. PV Solar Energy Conf., 1290 (2007).

• "a-Si/c-Si Heterojunction for Interdigitated Back Contact Solar Cell, "Meijun Lu, Stuart Bowden, Ujjwal Das and Robert Birkmire, Proc. 17th Workshop on Crystalline Silicon Solar Cells & Modules, (2007).

• "Effect of Surface Passivation on Si Heterojunction and Interdigitated Back Contact Solar Cells," U.K. Das, S. Bowden, M.Burrows, M. Lu and R.W. Birkmire, Proc. 17th Workshop on Crystalline Silicon Solar Cells & Modules, (2007).

• "Two Dimensional Modeling of Interdigitated Back Contact Silicon Heterojunction Solar Cells," Meijun Lu, Stuart Bowden, Robert Birkmire, Proc. IEEE NUSOD Int'l Conf. 10.1109/NUSOD.2007.4349021, 55-56 (2007).

2006

• "Comparison of Device Performance and Measured Transport Parameters in Widely-Varying Cu(In,Ga)(Se,S) Solar Cells," I. L. Repins, B. J. Stanbery, D.L. Young, S.S. Li, W.K. Metzger, C.L. Perkins,W.N. Shafarman, M.E. Beck, L. Chen, V.K. Kapur, D. Tarrant, M.D. Gonzalez, D.G. Jensen, T.J.Anderson, X. Wang, L.L. Kerr, B. Keyes, S. Asher, A. Delahoy and B Von Roedern, Prog. Photovolt: Res. Appl. 14, 25 (2006).

• "Sulfur Incorporation into Copper Indium Diselenide Single Crystals Through Annealing in Hydrogen Sulfide," Jochen Titus, Robert W. Birkmire, Christina Hack, Georg Muller, and Patrick McKeown, J. Appl. Phys. 99, 043502 (2006).

• "Controlling Growth Chemistry and Morphology of Single-Bath Electrodeposited Cu(In,Ga)Se2 Thin Films for Photovoltaic Application," M. Estela Calixto, Kevin D. Dobson, Brian E. McCandless and Robert W. Birkmire, J. Electrochem. Soc. 153(6), G521 (2006).

• "Thin Film Solar Modules: The Low Cost, High Throughput and Versatile Alternative to Si Wafers," S. Hegedus, Prog. Photovolt: Res. Appl.14, 393 (2006).

• "Role of Bulk Defect States in Limiting CIGS Device Properties," JinWoo Lee, Jennifer T. Heath. J. David Cohen and William N. Shafarman, Proc. 32nd IEEE PVSC and WCPEC-4, 360 (2006).

• "Electronic Properties of Wide Bandgap Penetenary Chalcopyrite Alloys and their Photovoltaic Devices," Adam Halverson, Shiro Nishiwaki, William Shafarman and J. David Cohen, Proc. 32nd IEEE PVSC and WCPEC-4, 364 (2006).

• "How CdTe Solar Cells Operate: Determining Collection Using Befacial Device Characterization," D. Desai, S. Hegedus, B. McCandless, R. Birkmire, K. Dobson, D. Ryan, Proc. 32nd IEEE PVSC and WCPEC-4, 368 (2006).

• "Characterization of Cu(InGa)Se2 Solar Cells Using Etched Absorber Layers," William N. Shafarman, Rongxue S. Huang, Scott H. Stephens, Proc. 32nd IEEE PVSC and WCPEC-4, 420 (2006).

• "Preparation of Wide Bandgap Cu(InGa)(SeS)2 Solar Cells with Improved Fill Factor," Shiro Nishiwaki and William N. Shafarman, Proc. 32nd IEEE PVSC and WCPEC-4, 461 (2006).

• "Thin Film Cadmium Zinc Telluride Solar Cells," Brian E. McCandless, Wayne A. Buchanan and Gregory M. Hanket, Proc.32nd IEEE PVSC and WCPEC-4, 483 (2006).

• "Composition Control in the Growth of Cu(InGa)(SeS)2 by the Reaction of Cu-In-Ga Precursors in H2Se and H2S," Gregory M. Hanket, William N. Shafarman, Robert W. Birkmire, Proc. 32nd IEEE PVSC and WCPEC-4, 560 (2006).

• "Effect of Process Paramater Variation in Deposited Emitter and Buffer Layers on the Performance of Silicon Heterojunction Solar Cells," Ujjwal Das, Stuart Bowden, Michael Burrows, Steven Hegedus and Robert Birkmire, Proc. 32nd IEEE PVSC and WCPEC-4, 1283 (2006).

• "Carrier Lifetime as a Developmental and Diagnostic Tool in Silicon Heterojunction Solar Cells," S. Bowden, U.K. Das, S.S. Hegedus, R.W. Birkmire, Proc. 32nd IEEE PVSC and WCPEC-4, 1295 (2006).

• "Design Strategy for Scale-Up of Physical Vapor Deposition of Cu(InGa)Se2 on Flexible Substrates," Kapil Mukati, Babatunde A. Ogunnaike, Erten Eser, Shannon Fields, Robert W. Birkmire, Proc. 32nd IEEE PVSC and WCPEC-4, 1842 (2006).

• "Surface Sulfurization Studies of Cu(InGa)Se2 Thin Film," Udai P. Singh, William N. Shafarman, Robert W. Birkmire, Solar Energy Mat. & Solar Cells 90, 623 (2006).

• "Break-even Price Estimates for Residental PV Applications in OECD Countries with an Analysis of Prospective Cost Reductions," Daniele Poponi, John Bryne and Steven Hegedus, Energy Studies Rev. 14(1), 104 (2006).

• "Oxygen Pressure Dependence of Copper Ion Transport in SiO2 Dielectrics," L.P. Shepherd, A. Matthew, B.E. McCandless, and B.G. Willis, J. Vac. Sci. Technol. B 24(3), 1287 (2006).

• "Void Formation and Surface Energies in Cu(InGa)Se2," C. Lei, A. Rockett, I.M. Robertson, W.N. Shafarman and M. Beck, J. Appl. Phys. 100, 073518 (2006).

• "Design of a Vapor Transport Deposition Process for Thin Film Materials," G.M. Hanket, B.E. McCandless, W.A. Buchanan, S. Fields, and R.W. Birkmire, J. Vac. Sci. and Technol. A, 24(5), 1695 (2006).