Ultrathin amorphous zinc-tin-oxide buffer layer for enhancing heterojunction interface quality in metal-oxide solar cells
Energy & Environmental Science (in press, DOI:10.1039/C3EE24461J)
Publications
Journal Articles
Origins of Structural Hole Traps in Hydrogenated Amorphous Silicon
Physical Review Letters 110, 146805 (2013).
Residual stress and dislocations density in silicon ribbons grown via optical zone melting
Journal of Applied Physics 113, 083510 (2013).
Interfaces between water splitting catalysts and buried silicon junctions
Energy & Environmental Science 6, 532-538 (2013).
Modeling integrated photovoltaic–electrochemical devices using steady-state equivalent circuits
Proceedings of the National Academy of Sciences (in press, DOI:10.1073/pnas.1301532110).
Featured in MIT News
Enhancing the efficiency of SnS solar cells via band-offset engineering with a zinc oxysulfide buffer layer
Applied Physics Letters 102, 053901 (2013).
Precipitated Iron: A Limit on Gettering Efficacy in Multicrystalline Silicon
Journal of Applied Physics 133, 044521 (2013).
Organic Vapor Passivation of Silicon at Room Temperature
Advanced Materials 25, 2078–2083 (2013)
Featured in MIT News
Analysis of the Evolution of Iron Precipitates in Multicrystalline Silicon During Solar Cell Processing
IEEE Journal of Photovoltaics 3, 131-137 (2013).
Modeling the Cost and Minimum Sustainable Price of Crystalline Silicon Photovoltaic Manufacturing in the United States
IEEE Journal of Photovoltaics 3, 662-668 (2013).
For the model and additional information please visit the MIT PV Lab TMA page.
Low contact resistivity of metals on nitrogen-doped cuprous oxide (Cu2O) thin-films
Journal of Applied Physics 112, 084508 (2012).
Dislocation Density Reduction During Impurity Gettering in Multicrystalline Silicon
IEEE Journal of Photovoltaics 3, 189-198 (2013).
Engineering metal precipitate size distributions to enhance gettering in multicrystalline silicon
Physica Status Solidi A 209, 1861-1865 (2012).
Controlling dopant profiles in hyperdoped silicon by modifying dopant evaporation rates during pulsed laser melting.
Applied Physics Letters 100, 112112 (2012).
Synchrotron-based microprobe investigation of impurities in raw quartz- and carbon-bearing feedstock materials for photovoltaic applications.
Progress in Photovoltaics 20, 217–225 (2012).
Crystalline silicon photovoltaics: A cost analysis framework for determining technology pathways to reach baseload electricity costs.
Energy & Environmental Science 5, 5874-5883 (2012).
Featured in The Economist, Tech Review
Structural origins of intrinsic stress in amorphous silicon thin films.
Physical Review B 85, 075202 (2012).
Insulator-to-metal transition in selenium-hyperdoped silicon: Observation and origin.
Physical Review Letters 108, 026401 (2012).
High photocurrent in silicon photoanodes catalyzed by iron-oxide thin films for water splitting.
Angewandte Chemie International Edition 51, 423–427 (2012).
Soft x-ray emission spectroscopy studies of the electronic structure of silicon supersaturated with sulfur.
Applied Physics Letters 99, 142102 (2011).
Nanoprobe X-ray fluorescence characterization of defects in large-area solar cells.
Energy & Environmental Science 4, 4252–4257 (2011).
Towards the tailoring of P diffusion gettering to as-grown silicon material properties.
Solid State Phenomena 178–179, 158–165 (2011).
Extended infrared photoresponse and gain in chalcogen-supersaturated silicon photodiodes.
Applied Physics Letters 99, 073503 (2011).
Light-induced water oxidation at silicon electrodes functionalized with a cobalt oxygen-evolving catalyst.
Proceedings of the National Academy of Sciences 108, 10056 (2011).
Featured in MIT News
Reactivation of sub-bandgap absorption in chalcogen-hyperdoped silicon.
Applied Physics Letters 98, 251905 (2011).
Impurity-to-efficiency simulator: Predictive simulation of silicon solar cell performance based on iron content and distribution.
Progress in Photovoltaics 19, 487–497 (2011).
Hall mobility of cuprous oxide thin films deposited by reactive direct-current magnetron sputtering.
Applied Physics Letters 98, 192115 (2011).
Iron distribution in silicon after solar cell processing: Synchrotron analysis and predictive modeling.
Applied Physics Letters 98, 162103 (2011).
Influence of defect type on hydrogen passivation efficacy in multicrystalline silicon solar cells.
Progress in Photovoltaics 19, 187–191 (2011).
Enhanced iron gettering by short, optimized low-temperature annealing after phosphorus emitter diffusion for industrial silicon solar cell processing.
Physica Status Solidi (c) 8, 759–762 (2011).
Stress-enhanced dislocation density reduction in multicrystalline silicon.
Physica Status Solidi Rapid Research Letters 5, 28-30 (2011).
Retrograde melting and internal liquid gettering in silicon.
Advanced Materials 22, 3948-3953 (2010).
Infrared birefringence imaging of residual stress and bulk defects in multicrystalline silicon
Journal of Applied Physics 108, 063528 (2010).
Dislocation density reduction in multicrystalline silicon solar cell material by high temperature annealing.
Applied Physics Letters 93, 122108 (2008).
Iron point defect reduction in multicrystalline silicon solar cells.
Applied Physics Letters 92, 122103 (2008).
Transition metal interaction and Ni-Fe-Cu-Si phases in silicon.
Journal of Applied Physics 101, 123510 (2007).
Physical mechanisms of in situ surface gettering of metals in ribbon silicon for solar cells.
Applied Physics Letters 90, 102110 (2007).
Control of metal impurities in “dirty” multicrystalline silicon for solar cells.
Materials Science and Engineering B 134, 282-286 (2006).
(Review Article) Chemical natures and distributions of metal impurities in multicrystalline silicon materials.
Progress in Photovoltaics: Research and Applications 14, 513-531 (2006).
Metal precipitation at grain boundaries in silicon: Dependence on grain boundary character and dislocation decoration.
Applied Physics Letters 89, 042102 (2006).
Complex intermetallic phase in multicrystalline silicon doped with transition metals for low-cost solar cells.
Physical Review B 73, 235204 (2006).
Transition metals in photovoltaic-grade cast multicrystalline silicon: Assessing the role of impurities in silicon nitride crucible lining material.
Journal of Crystal Growth 287, 402-407 (2006).
Local measurements of diffusion length and chemical character of metal clusters in multicrystalline silicon.
Solid State Phenomena 108-109, 577-584 (2005).
Impact of metal silicide precipitate dissolution during rapid thermal processing of multicrystalline silicon solar cells.
Applied Physics Letters 87, 121918 (2005).
Engineering metal-impurity nanodefects for low-cost solar cells.
Nature Materials 4, 676-679 (2005).
Quantifying the effect of metal-rich precipitates on minority carrier diffusion length in multicrystalline silicon using synchrotron-based spectrally-resolved X-ray beam induced current.
Applied Physics Letters 87, 044101 (2005).
Synchrotron-based investigations of the nature and impact of iron contamination in multicrystalline silicon solar cells.
Journal of Applied Physics 97, 074901 (2005).
Analysis of copper-rich preciptiates in silicon: chemical state, gettering, and impact on multicrystalline silicon solar cell material.
Journal Applied Physics 97, 063503 (2005).
Observation of transition metals at shunt locations in multicrystalline silicon solar cells.
Journal of Applied Physics 95 1556-1561 (2004).
X-ray beam induced current/microprobe x-ray fluorescence: synchrotron radiation based x-ray microprobe techniques for analysis of the recombination activity and chemical nature of metal impurities in silicon.
Journal of Physics: Condensed Matter 16, S141-S151 (2004).
Applications of synchrotron radiation x-ray techniques on the analysis of the behavior of transition metals in solar cells and single crystalline silicon with extended defects.
Physica B 340-342, 1137-1141 (2003).
Metal content of multicrystalline silicon for solar cells and its impact on minority carrier diffusion length.
Journal of Applied Physics 94, 6552-6559 (2003).
Metal content of multicrystalline silicon for solar cells.
Solid State Phenomena 95-96, 175-180 (2003).
Application of synchrotron radiation based x-ray microprobe techniques for the analysis of recombination activity of metals precipitated at Si/SiGe misfit dislocations.
Journal of Physics: Condensed Matter 14, 13079-13086 (2002).
X-ray beam induced current – a synchrotron radiation based technique for the in situ analysis of recombination properties and chemical nature of metal clusters in silicon.
Journal of Applied Physics 91, 3614-3617 (2002).
Conference Proceedings
Co-Optimizing Crystalline Silicon Solar Cell Throughput and Efficiency Using Continuously Ramping Phosphorus Diffusion Profiles
Materials Research Society Fall Meeting & Exhibit Boston, MA, November 25-30 (2012)
Simulated Co-Optimization of Crystalline Silicon Solar Cell Throughput and Efficiency Using Continuously Ramping Phosphorus Diffusion Profiles
Proc. 38th IEEE Photovoltaic Specialists Conference, Austin, TX, USA (2012).
Raman Study of Localized Recrystallization of Amorphous Silicon Induced by Laser Beam
Proc. 38th IEEE Photovoltaic Specialists Conference, Austin, TX, USA (2012).
Detection of ZnS phases in CZTS thin-films by EXAFS.
Proc. 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA (2011).
Stress engineering in amorphous silicon thin films.
Proc. 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA (2011).
High-mobility copper (I) oxide thin films prepared by reactive DC magnetron sputtering for photovoltaic applications.
Proc. 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA (2011).
Deployment of impurity-to-efficiency (I2E) simulation tool.
Proc. 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA (2011).
Synchrotron-based characterization of solar cell nanodefects.
Proc. 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA (2011).
Effective iron gettering in lightly-doped emitters.
Proc. 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA (2011).
Impurity-to-efficiency simulator: Predictive simulation of solar cell efficiencies based on measured metal distribution and cell processing conditions.
Proc. 25th European Photovoltaic Solar Energy Conference, Valencia, Spain (2010).
See also: Journal Article
Synchrotron-based microanalysis of iron distribution after thermal processing and predictive modeling of resulting solar cell efficiency.
Proc. 35th IEEE Photovoltaic Specialists Conference, Honolulu, HI (2010).
Infrared birefringence imaging of residual stress and bulk defects in multicrystalline silicon.
Proc. 35th IEEE Photovoltaic Specialists Conference, Honolulu, HI (2010).
See also: Journal Article
Stress and temperature coupling effects on dislocation density reduction in multicrystalline silicon.
Proc. 35th IEEE Photovoltaic Specialists Conference, Honolulu, HI (2010).
See also: Journal Article
Impact of defect type on hydrogen passivation effectiveness in multicrystalline silicon solar cells.
Proc. 35th IEEE Photovoltaic Specialists Conference, Honolulu, HI (2010).
See also: Journal Article
Insights into the optimal phosphorus diffusion profile for silicon solar cells.
Proc. 24th European Photovoltaic Solar Energy Conference, Hamburg, Germany (2009) pp.1893-1896.
Quantitative stress measurements of bulk microdefects in multicrystalline silicon.
Proc. 24th European Photovoltaic Solar Energy Conference, Hamburg, Germany (2009) pp.977-980.
Simulating the evolution of the impurity content and distribution in a mc-Si wafer during solar cell processing.
Proc. 24th European Photovoltaic Solar Energy Conference, Hamburg, Germany (2009) pp.2019-2022.
Illuminating the mechanism for sub-bandgap absorption in chalcogen-doped silicon materials for PV applications.
Proc. 24th European Photovoltaic Solar Energy Conference, Hamburg, Germany (2009) pp.236-238.
Earth-abundant materials for high-efficiency heterojunction thin-film solar cells.
Proc. 34th IEEE Photovoltaic Specialists Conference, Philadelphia, USA (2009) pp.696-699.
Mitigating the “iron problem” in crystalline silicon solar cells
Proc. 23rd European Photovoltaic Solar Energy Conference and Exhibition, Valencia, Spain (2008).
Defect redistribution by low temperature anneal in ingot silicon solar cells
Proc. 23rd European Photovoltaic Solar Energy Conference and Exhibition, Valencia, Spain (2008).
Evolution of metal impurities during crystalline silicon solar cell processing
Proc. 33rd IEEE Photovoltaic Specialists Conference, San Diego, USA (2008).
Luminescence Imaging.
Proc. 22nd European Photovoltaic Solar Energy Conference and Exhibition, Milan, Italy (2007).
Intermetallic phases and transition metal interaction in mc-silicon.
Proc. 22nd European Photovoltaic Solar Energy Conference and Exhibition, Milan, Italy (2007).
Evolution of stresses in wafer bulks and edges during industrial solar cell processing
Proc. 22nd European Photovoltaic Solar Energy Conference and Exhibition, Milan, Italy (2007).
Nature, impact, and remediation of the principal lifetime-limiting defects in String Ribbon material.
Proc. 21st European Photovoltaic Solar Energy Conference and Exhibition, Dresden, Germany (2006) pp.1505-1507.
Transition metal interaction and formation of intermetallic phases in multicrystalline silicon.
Proc. 21st European Photovoltaic Solar Energy Conference and Exhibition, Dresden, Germany (2006) pp.1105-1107.
From understanding towards engineering metal impurities in multicrystalline silicon.
Proc. 21st European Photovoltaic Solar Energy Conference and Exhibition, Dresden, Germany (2006) pp.696-699.
Interactions between metals and different grain boundary types and their impact on multicrystalline silicon device performance.
Proc. 4th World Conference on Photovoltaic Energy Conversion, Waikoloa, Hawaii, USA (2006) pp. 944-947.
Correlations between structural, impurity, and electrical properties in efficiency-limiting “defect bands” in string ribbon silicon
Proc. 20th European Photovoltaic Solar Energy Conference and Exhibition, Barcelona, Spain (2005).
Technology choices for the PV industry: A comparative life cycle environmental impact perspective
Proc. 20th European Photovoltaic Solar Energy Conference and Exhibition, Barcelona, Spain (2005).
Distinguishing the impacts of individual metal species on multicrystalline silicon performance in a multiple metal environment
Proc. 20th European Photovoltaic Solar Energy Conference and Exhibition, Barcelona, Spain (2005).
Distribution and formation of silicon carbide and silicon nitride precipitates in block-cast multicrystalline silicon
Proc. 20th European Photovoltaic Solar Energy Conference and Exhibition, Barcelona, Spain (2005).
Synchrotron-based investigations into metallic impurity distribution and defect engineering in multicrystalline silicon via thermal treatments
Proc. 31st IEEE Photovoltaic Specialists Conference (Lake Buena Vista, USA) pp.1027-1030 (2005).
Impact of iron contamination in multicrystalline silicon solar cells: Origins, chemical states, and device impacts
Proc. 19th European Photovoltaic Solar Energy Conference and Exhibition, Paris, France, pp.488-491 (2004).
Defects in the deteriorated border layer of block-cast multicrystalline silicon ingots
Proc. 19th European Photovoltaic Solar Energy Conference and Exhibition, Paris, France, pp.762-765 (2004).
Assessing the role of transition metals in shunting mechanisms using synchrotron-based techniques
Proc. 3rd World Photovoltaic Specialists Conference (WCPEC-3), Osaka, Japan, pp.1120-1123 (2003).
Application of x-ray synchrotron techniques to the characterization of the chemical nature and recombination activity of grown-in and process-induced defects and impurities in solar cells
MRS Symposium Proceedings 719, p.179 (2002).
Workshop Proceedings
Co-optimizing the Phosphorous Diffusion Time-Temperature Profile for Gettering and Throughput
5th International Workshop on Crystalline Silicon Solar Cells - CSSC-5 , Boston, USA 1–3 November (2011)
Rapid dislocation-density mapping of as-cut crystalline-silicon wafers
6th International Workshop on Crystalline Silicon Solar Cells, Aix-les-Bains, France (2012).
Impurity analysis in silicon- and carbon-bearing raw feedstock materials.
3rd International Workshop on Crystalline Silicon Solar Cells, Trondheim, Norway (2009).
Electrical and Mechanical Defects in Solar Cell Materials and Devices
4th Workshop on the Future Direction of Photovoltaics, Japanese Society for the Promotion of Science, Tokyo, Japan (2008).
Reducing the concentration of interstitial iron in crystalline silicon solar cells via low (≤ 500°C) temperature annealing.
17th workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, Editor: B.L.Sopori, NREL, Golden, CO (2007).
Synchrotron-based infrared spectromicroscopy of oxygen gettering by grain boundaries in multicrystalline silicon.
15th workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, Editor: B.L.Sopori, NREL, Golden, CO, pp.178-181 (2005).
Metal particle evolution during solar cell processing in multicrystalline silicon.
15th workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, Editor: B.L.Sopori, NREL, Golden, CO, pp.174-177 (2005).
Efficiency-limiting ‘defect bands’ in string ribbon silicon: correlations between structural, impurity, and electrical properties.
15th workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, Editor: B.L.Sopori, NREL, Golden, CO, pp.170-173 (2005).
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.
15th workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, Editor: B.L.Sopori, NREL, Golden, CO, pp.166-169 (2005).
Assessing the role of impurities in silicon nitride crucible lining material as a potential source of metal contamination in photovoltaic-grade ingot-cast multicrystalline silicon.
15th workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, Editor: B.L.Sopori, NREL, Golden, CO, pp.162-165 (2005).
EXAFS studies on Ni11.6Fe2.8Cu0.4Si27.6 precipitates in multicrystalline silicon.
15th workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, Editor: B.L.Sopori, NREL, Golden, CO, pp.158-161 (2005).
Transition metals in silicon solar cells: sources of contamination, interactions, defect engineering.
15th workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, Editor: B.L.Sopori, NREL, Golden, CO, pp.70-77 (2005).
Improvement of solar grade silicon through defect control
Freiberger Siliciumtage, Freiberg, Germany (2005).
The impact of chemical state and thermal stability of metal precipitates on gettering efficiency in silicon
Proc. 4th International Symposium on Advanced Science and Technology of Silicon Materials, Kona, Hawaii, USA (2004).
The impact of metal impurity clusters on solar cell performance in multicrystalline silicon
Proc. 2004 National Center for Photovoltaics Review Meeting, Denver, USA (2004).
Differences and similarities between metal clusters in mc-Si materials from different manufacturers
Proc. 14th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Winter Park, CO, pp.226-229 (2004).
Aluminum gettering and dissolution of Cu3Si precipitates in silicon
Proc. 14th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Winter Park, CO, pp.222-225 (2004).
Stress-induced nitrogen and oxygen segregation and complexing investigated by high resolution synchrotron FTIR
Proc. 14th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Winter Park, CO, pp.204-207 (2004).
Dependence of precipitation behavior of Cu and Ni in CZ and multicrystalline silicon on cooling conditions
Proc. 14th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Winter Park, CO, pp.165-169 (2004).
Distribution and chemical state of Cu-rich clusters in silicon
Proc. 14th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Winter Park, CO, pp.161-164 (2004).
Transition metals in multicrystalline solar cells: Understanding the nature, origins and impacts of metal contamination in multicrystalline Si and minimizing its impact on solar cell performance
Proc. 14th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Winter Park, CO, pp.17-26 (2004).
Neutron activation analysis study of metal content of multicrystalline silicon for cost-efficient solar cells
Proc. 13th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Vail, CO, pp.158-161 (2003).
Experimental procedure for determination of the depth of metal clusters in XBIC/µ-XRF mapping of metal clusters in silicon solar cells
Proc. 13th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Vail, CO, pp.102-105 (2003).
Statistically meaningful data on the chemical state of iron precipitates in processed multicrystalline silicon using synchrotron-based x-ray absorption spectroscopy
Proc. 13th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Vail, CO, pp.96-101 (2003).
Impact of metal impurities on solar cell performance
Proc. 2003 National Center for Photovoltaics Review Meeting, Denver, USA (2003).
Application of synchrotron radiation based x-ray microprobe techniques for the analysis of recombination activity of metals precipitated at Si/SiGe misfit dislocations
Proc. 12th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Breckenridge, CO, pp.111-116 (2002).
Application of x-ray fluorescence technique to studies of aluminum gettering in silicon
Proc. 12th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Breckenridge, CO, pp.271-274 (2002).
Analysis of shunts in multicrystalline silicon solar cells using microprobe x-ray fluorescence technique
Proc. 12th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Breckenridge, CO, pp.266-270 (2002).
Application of x-ray fluorescence microprobe technique for the analysis of fully processed solar cells
Proc. 11th workshop on crystalline silicon solar cell materials and processes, B. L. Sopori, Editor, NREL, Golden, CO, pp.172-176 (2001).
Presentations
The Bright Future of Silicon-Based Photovoltaics.
Invited talk at the Intersolar North America Conference, San Francisco, California, USA (2008).
Electrical and Mechanical Defects in Solar Cell Materials and Devices.
Invited talk at the 4th Workshop on the Future Direction of Photovoltaics, Japanese Society for the Promotion of Science, Tokyo, Japan (2008).
Evolution of stresses in wafer bulks and edges during industrial solar cell processing.
Plenary presentation at the 22nd European Photovoltaic Solar Energy Conference and Exhibition, Milan, Italy (2007).