A national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy National Renewable Energy Laboratory Innovation for Our Energy Future th Proceedings 15 Workshop on Crystalline NREL/BK-520-38573 Silicon Solar Cells and Modules: November 2005 Materials and Processes Extended Abstracts and Papers Workshop Chairman/Editor: B.L. Sopori Program Committee: M. Al-Jassim, J. Kalejs, J. Rand, T. Saitoh, R. Sinton, M. Stavola, R. Swanson, T. Tan, E. Weber, J. Werner, and B. Sopori Vail Cascade Resort Vail, Colorado August 7–10, 2005 NREL is operated by Midwest Research Institute ● Battelle Contract No. DE-AC36-99-GO10337 th Proceedings 15 Workshop on Crystalline NREL/BK-520-38573 Silicon Solar Cells and Modules: November 2005 Materials and Processes Extended Abstracts and Papers Workshop Chairman/Editor: B.L. Sopori Program Committee: M. Al-Jassim, J. Kalejs, J. Rand, T. Saitoh, R. Sinton, M. Stavola, R. Swanson, T. Tan, E. Weber, J. Werner, and B. 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Fisher Designs and Fabrication Technologies for Future Commercial Crystalline Si Solar Cells . 11 Ajeet Rohatgi Atomic Structure and Electronic Properties of c-Si/a-Si:H Interfaces in Silicon Heterojunction Solar Cells . 23 Yanfa Yan, Q. Wang, M. Page, E. Iwaniczko, D. Levi, M. M. Al-Jassim, Howard M. Branz, and T.H. Wang Design and Operational Considerations for Crystalline Silicon PV Modules . 29 Adrianne Kimber Modeling CZ Crystal Growth and Casting Process for Solar Cells . 30 Koichi Kakimoto, Lijun Liu, and Satoshi Nakano Application of Numerical Simulation of Directional Solidification Processes for Improving Crystal Quality . 38 T. Saitoh and I. Yamaga Solar Industry Crystalline Silicon Initiative: A Step on the Road to Our Solar Power Future . 48 Allen Barnett and Rhone Resch European Photovoltaic RTD and Demonstration Programme . 51 P. Menna DOE Photovoltaics Subprogram – Crystalline Silicon . 56 Jeffrey Mazer Transition Metals in Silicon Solar Cells: Sources of Contamination, Interactions, Defect Engineering . 65 A. A. Istratov, T. Buonassisi, M. Heuer, M. Pickett, and E. R. Weber Nature of the Metastable Boron-oxygen Complex in Crystalline Silicon . 73 Richard Crandall iii Passivating Multi Crystalline Si Solar Cells Using SiNx:H . 80 I. G. Romijn, W. J. Soppe, H. C. Rieffe, W. C. Sinke, and A. W. Weeber AKT Thin Film PECVD Deposition . 88 Robert Bachrach Overview and Results of the German Research Network Project ASIS (Alternative Silicon for Solar Cells) . 101 D. Karg and W. Koch New Approaches to Solar-grade Silicon Feedstock and Silane Productions . 109 T. H. Wang, M. R. Page, T. F. Ciszek, M. F. Tamendarov, and B. N. Mukashev Production of Solar Grade Silicon by an Ethanol Process . 113 E. P. Belov, N. K. Efimov, E. N. Lebedev, V. V. Zadde, A. B. Pinov, D. S. Strebkov, D. M. Blake, and K. Touryan Mechanical Strength of Silicon Wafers and Its Modelling . 117 G. Coletti, C. J. J. Tool and L. J. Geerligs Development of Low Stress Aluminum Back Surface Field Pastes . 121 C. Khadilkar, S. Kim, and A. Shaikh Fundamental Investigations and Proposed Solutions to Make the Alloyed Al BSF Ready for the Demands of Future Cell Production . 128 Frank Huster Lead-free Solder Issues in Microelectronics . 129 J. W. Morris Jr. Spectrum Imaging: Fulfilling a Vision in Cathodoluminescence Instrumentation . 132 M. J. Romero, M. M. Al-Jassim, and P. Sheldon Poster Papers: Non-radiative Carrier Recombination at Metastable Light-induced Boron-oxygen Complexes in Silicon . 137 Mao-Hua Du, Howard M. Branz, Richard S. Crandall, and S. B. Zhang Synchrotron-based Spectrally-resolved X-ray Beam Induced Current: A Technique to Quantify the Effect of Metal-rich Precipitates on Minority Carrier Diffusion Length in Multicrystalline Silicon . 141 T. Buonassisi, A. A. Istratov, M. D. Pickett, M. A. Marcus, G. Hahn, S. Riepe, J. Isenberg, W. Warta, G. Willeke, T. F. Ciszek, and E. R. Weber Metal Particle Evolution During Solar Cell Processing in Multicrystalline Silicon . 145 Tonio Buonassisi, Matthew D. Pickett, Andrei A. Istratov, Erik Sauar, Roger F. Clark, Mohan Narayanan, Steven M. Heald, and Eicke R. Weber Defects Induced by Impurity Atoms in B-doped Cast-grown Polycrystalline Silicon . 149 Yoshio Ohshita, Koji Arafune, Hitoshi Sai and Masafumi Yamaguchi iv Hydrogen-rich Silicon Nitride Layers: Surface and Bulk Passivation for Solar Cell Applications . 153 Chuan Li, Bhushan Sopori, P. Rupnowski, Anthony T. Fiory, and N. M. Ravindra 21% Efficient Si Solar Cell Using a Low-temperature a-Si:H Back Contact . 158 P. J. Rostan, U. Rau, V. X. Nguyen, T. Kirchartz, M. B. Schubert, and J. H. Werner Structure, Electrical Activity, and Thermal Stability of Acceptor-oxygen Complexes in Si Solar Cells . 162 M. Sanati, S. K. Estreicher, and D. West Photoluminescence: A Versatile Characterization Technique for Crystalline Silicon . 166 T. Trupke and R. A. Bardos Silicon PV Technology at a Crossroad? . 170 Bolko von Roedern Progress in the Use of Hot-Wire CVD a-Si:H as Emitters and Collectors in Silicon Heterojunction Solar Cells . 174 T. H. Wang, M. R. Page, E. Iwancizko, Y. Xu, Q. Wang, Y. Yan, D. Levi, V. Yelundur, L. Roybal, R. Bauer, A. Rohatgi, and H. M. Branz Correlation Between Wafer Fracture and Saw Damage Introduced During Cast Silicon Cutting . 178 Y. K. Park, M. C. Wagener, N. Stoddard, M. Bennett, and G. A. Rozgonyi Investigation of Intragrain Lifetime Dependence in Cast Polycrystalline Silicon . 182 J. K. L. Peters, M. C. Wagener, M. Narayanan, and G. A. Rozgonyi PV Manufacturing Initiative . 186 S. Danyluk, S. Melkote, A. Dugenske, S. He, F. Li, X. Brun, and D. Furbush Analysis and Determination of the Stress-optic Coefficients of EFG Silicon . 189 S. He, F. Li, and S. Danyluk Effect of Oxygen on the Quality of Al-BSF in Si Cells . 193 V. Meemongkolkiat, K. Nakayashiki, B. C. Rounsaville, and A. Rohatgi Resonance Ultrasonic Vibration (RUV) for Crack Detection in PV Crystalline Silicon . 197 A. Belyaev, W. Dallas, O. Polupan, L. Zhukov, and S. Ostapenko High Efficiency Thin Multicrystalline Silicon Solar Cells . 201 Manav Sheoran, Ajay Upadhyaya, Ajeet Rohatgi, David E. Carlson, and Mohan Narayanan Approach Towards 20% Efficient Screen-printed Crystalline Silicon Solar Cells . 205 A. Ebong, M. Hilali, B. Rounsaville, and A. Rohatgi Wafering Research at Fraunhofer ISE . 211 D. Kray, S. Baumann, K. Mayer, F. Haas, M. Schumann, M. Bando, A. Eyer, and G. P. Willeke v Determination of Impurities Introduced During Solid Phase Crystallization of Amorphous Silicon Thin Films . 215 Robert C. Reedy, Eugene Iwaniczko, Qi Wang, Yueqin Xu, and David Young Dislocation Generation by Thermal Stresses in Silicon . 216 Bhushan Sopori, Przemyslaw Rupnowski, Davor Balzar, and Pete Sheldon Polishing Multicrystalline Silicon Wafers . 222 Bhushan Sopori, Peter Rupnowski, Bryan Taliaferro, Doug Gagnon, and Chuan Li Characterizing Thin Films on Highly Absorbing Substrates . 229 Bhushan Sopori, Juana Ameiva, and Peter Rupnowski vi Silicon Workshop: Providing the Scientific Basis for Industrial Success Bhushan Sopori National Renewable Energy Laboratory The silicon photovoltaic (PV-Si) industry has undergone rapid growth in the last few years, leading to new production capabilities that will exceed GW/yr and take us to multi-GW production in the near future. This rapid growth was fostered by many technical achievements and breakthroughs in the science and technology of photovoltaics. Some of these technologies were developed by the industry itself while others were adopted from R&D performed at various universities and academic institutions. These technical and scientific advances have occurred around the globe and, in many cases, were prompted by strong government assistance.