Publications

Book Chapters

  1. S. A. Ringel, T. J. Grassman, “Chapter 14: III-V Solar Cells on Silicon” in III-V Compound Semiconductors: Integration with Silicon-Based Microelectronics, edited by T. Li, M. Mastro, A. Dadgar (CRC Press, Boca Raton, FL, 2011).

Journal Articles and Proceedings

  1. C. M. Jackson, A. R. Arehart, T. J. Grassman, B. McSkimming, J. S. Speck and S. A. Ringel, “Impact of Surface Treatment on Interface States of ALD Al2O3/GaN Interfaces,” ECS Journal of Solid State Science and Technology 6(8), P489 (2017).
  2. J. I. Deitz, P. K. Paul, S. Karki, S. Marsillac, A. R. Arehart, T. J. Grassman and D. W. McComb, “Detecting Sub Bandgap Energies in CIGS with Electron Energy-Loss Spectroscopy,” Microscopy and Microanalysis 23(S1), 1546 (2017).
  3. J. Demuth, E. Fahrenkrug, L. Ma, T. Shodiya, J. I. Deitz, T. J. Grassman, and S. Maldonado, “Electrochemical Liquid Phase Epitaxy (ec-LPE): A New Methodology for the Synthesis of Crystalline Group IV Semiconductor Epifilms,” Journal of the American Chemical Society 139(20), 6960 (2017).
  4. S. Karki, P. K. Paul, G. Rajan, T. Ashrafee, K. Aryal, P. Pradhan, R. W. Collins, A. Rockett, T. J. Grassman, S. A. Ringel, A. R. Arehart and S. Marsillac, “In Situ and Ex Situ Investigations of KF Postdeposition Treatment Effects on CIGS Solar Cells,” IEEE Journal of Photovoltaics 7(2), 665 (2017).
  5. J. I. Deitz, S. D. Carnevale, M. D. Graef, D. W. McComb, and T. J. Grassman, “Characterization of encapsulated quantum dots via electron channeling contrast imaging,” Applied Physics Letters 109(6), 062101 (2016).
  6. R. M. France, F. Dimroth, T. J. Grassman and R. R. King, “Metamorphic epitaxy for multijunction solar cells,” MRS Bulletin 41(3), 202 (2016).
  7. T. J. Grassman, D. J. Chmielewski, S. D. Carnevale, J. A. Carlin and S. A. Ringel, “GaAs0.75P0.25/Si Dual-Junction Solar Cells Grown by MBE and MOCVD,” IEEE Journal of Photovoltaics 6(1), 326 (2016).
  8. J. I. Deitz, D. W. McComb and T. J. Grassman, “Advancement of Heteroepitaxial III-V/Si Thin Films through Defect Characterization,” Microscopy and Microanalysis 22(S3), 1538 (2016).
  9. J. I. Deitz, T. J. Grassman and D. W. McComb, “Accessing High Spatial Resolution Low-Loss EELS Information without Cerenkov Radiation,” Microscopy and Microanalysis 22(S3), 976 (2016).
  10. T. J. Grassman, D. J. Chmielewski, J. A. Carlin and S. A. Ringel, “Development of epitaxial 2- and 3-junction III-V/Si solar cells,” 43rd IEEE Photovoltaic Specialists Conference, 2036-2039 (2016).
  11. D. J. Chmielewski, K. Galiano, P. Paul, D. Cardwell, S. Carnevale, J. A. Carlin, A. R. Arehart, T. J. Grassman and S. A. Ringel, “Comparative study of 2.05 eV AlGaInP and metamorphic GaInP materials and solar cells grown by MBE and MOCVD,” 43rd IEEE Photovoltaic Specialists Conference, 3411-3414 (2016).
  12. J. I. Deitz, D. W. McComb and T. J. Grassman, “Probing the electronic structure at the heterovalent GaP/Si interface using electron energy-loss spectroscopy,” 43rd IEEE Photovoltaic Specialists Conference, 1545-1548 (2016).
  13. P. K. Paul, K. Aryal, S. Marsillac, T. J. Grassman, S. A. Ringel and A. R. Arehart, “Identifying the source of reduced performance in 1-stage-grown Cu(In, Ga)Se2 solar cells,” 43rd IEEE Photovoltaic Specialists Conference, 3641-3644 (2016)
  14. E. García-Tabarés, J. A. Carlin, T. J. Grassman, D. Martín, I. Rey-Stolle and S. A. Ringel, “Evolution of silicon bulk lifetime during III–V-on-Si multijunction solar cell epitaxial growth,” Progress in Photovoltaics 24(5), 634 (2016).
  15. A. T. M. G. Sarwar, B. J. May, J. I. Deitz, T. J. Grassman, D. W. McComb and R. C. Myers, “Tunnel junction enhanced nanowire ultraviolet light emitting diodes,” Applied Physics Letters 107(10), 101103 (2015).
  16. P. K. Paul, D. W. Cardwell, C. M. Jackson, K. Galiano, K. Aryal, J. P. Pelz, S. Marsillac, S. A. Ringel, T. J. Grassman and A. R. Arehart, “Direct nm-Scale Spatial Mapping of Traps in CIGS,” IEEE Journal of Photovoltaics 5(5), 1482 (2015).
  17. I. A. Mansouri, S. Bremner, A. Ho-Baillie, H. Mehrvarz, X. Hao, G. Conibeer, T. J. Grassman, J. A. Carlin, A. Haas, S. A. Ringel and M. A. Green, “Designing Bottom Silicon Solar Cells for Multijunction Devices,” IEEE Journal of Photovoltaics 5(2), 683 (2015).
  18. J. I. Deitz, S. D. Carnevale, S. A. Ringel, D. W. McComb, T. J. Grassman, “Electron Channeling Contrast Imaging for Rapid III-V Heteroepitaxial Characterization,” Journal of Visualized Experiments (101), e52745 (2015).
  19. S. D. Carnevale, J. I. Deitz, J. A. Carlin, Y. N. Picard, M. De Graef, S. A. Ringel, T. J. Grassman, “Applications of Electron Channeling Contrast Imaging for the Rapid Characterization of Extended Defects in III-V/Si Heterostructures,” IEEE Journal of Photovoltaics 5(2), 676 (2015).
  20. J. I. Deitz, S. D. Carnevale, D. W. McComb, S. A. Ringel and T. J. Grassman, “Novel Applications of Electron Channeling Contrast Imaging,” Microscopy and Microanalysis 21(S3), 1897 (2015).
  21. J. I. Deitz, S. D. Carnevale, D. W. McComb, S. A. Ringel and T. J. Grassman, “Site-Specific TEM Specimen Preparation of Samples with Sub-Surface Features,” Microscopy and Microanalysis 21(S3), 2157 (2015).
  22. D. W. Cardwell, N. R. Vaughn, P. Paul, C. Ratcliff, D. J. Chmielewski, S. D. Carnevale, A. R. Arehart, T. J. Grassman, S. A. Ringel, “Investigations of Metamorphic (Al)GaInP for III-V Multijunction Photovoltaics,” Proc. 42nd IEEE Photovoltaic Specialist Conference, 10.1109/pvsc.2015.7355656 (2015).
  23. D. J. Chmielewski, S. D. Carnevale, T. J. Grassman, J. A. Carlin, S. A. Ringel, “High-Performance Metamorphic Tunnel Junctions for III-V/Si Multijunction Solar Cells,” Proc. 42nd IEEE Photovoltaic Specialists Conference, 10.1109/pvsc.2015.7356382 (2015).
  24. J. I. Deitz, S. D. Carnevale, S. A. Ringel, D. W. McComb, T. J. Grassman, “Extending Characterization Applications of Electron Channeling Contrast Imaging,” Proc. 42nd IEEE Photovoltaic Specialist Conference, 10.1109/pvsc.2015.7356198 (2015).
  25. E. Garcia-Tabares, T. J. Grassman, D. Martin, J. Carlin, I. Rey-Stolle and S. A. Ringel, “Evolution of the silicon bottom cell photovoltaic behavior during III-V on Si multi-junction solar cells production,” Proc. 42nd IEEE Photovoltaic Specialist Conference, 10.1109/pvsc.2015.7356380 (2015).
  26. T. J. Grassman, D. J. Chmielewski, S. D. Carnevale, J. A. Carlin and S. A. Ringel, “GaAsP/Si dual-junction solar cells grown by MBE and MOCVD,” Proc. 42nd IEEE Photovoltaic Specialist Conference, 10.1109/pvsc.2015.7356384 (2015).
  27. P. K. Paul, D. W. Cardwell, C. M. Jackson, K. Galiano, K. Aryal, J. P. Pelz, S. Marsillac, S. A. Ringel, T. J. Grassman and A. R. Arehart, “Direct nm-scale spatial mapping of traps in CIGS,” Proc. 42nd IEEE Photovoltaic Specialist Conference, 10.1109/pvsc.2015.7355656 (2015).
  28. J. I. Deitz, S. D. Carnevale, M. De Graef, Y. N. Picard, S. A. Ringel, T. J. Grassman, D. W. McComb, “Using Electron Channeling Contrast Imaging for Misfit Dislocation Characterization in Heteroepitaxial III-V/Si Thin Films,” Microscopy and Microanalysis 20(S3), 552-553 (2014).
  29. T. J. Grassman, J. A. Carlin, S. D. Carnevale, I. A. Mansouri, H. Mehrvarz, S. Bremner, A. Ho-Baillie, E. Garcia-Tabares, I. Rey-Stolle, M. A. Green and S. A. Ringe, “Progress toward a Si-plus architecture: epitaxially-integrable Si sub-cells for III-V/Si multijunction photovoltaics,” 40th IEEE Photovoltaic Specialists Conference, 10.1109/PVSC-Vol2.2014.7588253 (2014).
  30. D. J. Chmielewski, T. J. Grassman, A. M. Carlin, J. A. Carlin, A. J. Speelman, S. A. Ringel, “Metamorphic GaAsP Tunnel Junctions for High Efficiency III-V/IV Multijunction Solar Cell Technology,” IEEE Journal of Photovoltaics 4(5), 1301 (2014).
  31. S. D. Carnevale, J. I. Deitz, J. A. Carlin, Y.N. Picard, M. De Graef, S. A. Ringel, T. J. Grassman, “Rapid Misfit Dislocation Characterization in Heteroepitaxial III-V/Si Thin Films by Electron Channeling Contrast Imaging,” Applied Physics Letters 104(23), 232111 (2014).
  32. T. J. Grassman, J. A. Carlin, B. Galiana, F. Yang, M. J. Mills, S. A. Ringel, “MOCVD-Grown GaP/Si Subcells for Integrated III-V/Si Multijunction Photovoltaics,” IEEE Journal of Photovoltaics 4(3), 972 (2014).
  33. C. Ratcliff, T. J. Grassman, J. A. Carlin, D. J. Chmielewski, S. A. Ringel, “Ga-rich GaxIn1-xP solar cells on Si with 1.95 eV bandgap for ideal III-V/Si photovoltaics,” SPIE 8981: Physics, Simulation, and Photonic Engineering of Photovoltaic Devices III, 898118 (2014).
  34. M. A. Green, X. Hao, S. Bremner, G. J. Conibeer, I. A. Mansouri, N. Song, Z. Liu, S. A. Ringel, J. A. Carlin, T. J. Grassman, B. Galiana, A. M. Carlin, C. Ratcliff, D. Chmielewski, L. Yang, M. J. Mills, G. Teeter, M. Young, “Silicon Wafer-Based Tandem Cells: The Ultimate Photovoltaic Solution?,” Proc. 28th European Photovoltaic Solar Energy Conference, 7 (2013).
  35. T. J. Grassman, D. B. Shah, J. A. Carlin, S. A. Ringel, “Exploration of Epitaxial Quantum Dots within Wide Band Gap Metamorphic Host Materials for Intermediate Band Solar Cells,” Proc. 39th IEEE Photovoltaic Specialists Conference, 0284 (2013).
  36. T. J. Grassman, J. A. Carlin, C. Ratcliff, D. J. Chmielewski, S. A. Ringel, “Epitaxially-Grown Metamorphic GaAsP/Si Dual-Junction Solar Cells,” Proc. 39th IEEE Photovoltaic Specialists Conference, 0149 (2013).
  37. D. J. Chmielewski, T. J. Grassman, A. M. Carlin, C. Ratcliff, S. A. Ringel, “Metamorphic Tunnel Junctions for High Efficiency III-V/IV Multi-Junction Solar Cell Technology,” Proc. 39th IEEE Photovoltaic Specialists Conference, 0882 (2013).
  38. S. A. Ringel, J. A. Carlin, T. J. Grassman, B. Galiana, A. M. Carlin, C. Ratcliff, D. J. Chmielewski, L. Yang, M. J. Mills, I. Al-Mansouri, S. P. Bremner, A. Ho-Baillie, X. Hao, H. Mehrvarz, G. Conibeer, M. A. Green, “Ideal GaP/Si Heterostructures Grown by MOCVD: III-V/Active-Si Subcells, Multijuntions, and MBE-to-MOCVD III-V/Si Interface Science,” Proc. 39th IEEE Photovoltaic Specialists Conference, 3383 (2013).
  39. A. Haas, P. Sharps, D. Aiken, T. J. Grassman, J. A. Carlin, S. A. Ringel, “Analysis of Short- and Long-Term Performance Goals for III/V on Active Si Concentrator Solar Cells,” Proc. 39th IEEE Photovoltaic Specialists Conference, 0867 (2013).
  40. I. A. Mansouri, S. Bremner, A. Ho-Baillie, H. Mehrvarz, X. Hao, G. Conibeer, M. A. Green, T. J. Grassman, J. A. Carlin and S. A. Ringel, “Design of bottom silicon solar cell for multijunction devices,” Proc. 39th IEEE Photovoltaic Specialists Conference, 3310 (2013).
  41. T. J. Grassman, J. A. Carlin, B. Galiana, L.-M. Yang, F. Yang, M. J. Mills, S. A. Ringel, “Nucleation-related defect-free GaP/Si(100) heteroepitaxy via metal-organic chemical vapor deposition,” Applied Physics Letters 102(14), 142102 (2013).
  42. T. J. Grassman, C. Ratcliff, A. M. Carlin, J. A. Carlin, L.-M. Yang, M. J. Mills, S. A. Ringel, “III-V/GaP Epitaxy on Si for Advanced Photovoltaics and Green Light Emitters,” ECS Transactions 50(9), 321 (2013).
  43. A. M. Carlin, T. J. Grassman, M. R. Brenner, J. Grandal, C. Ratcliff, L.-M. Yang, M. J. Mills, P. Sharma, E. A. Fitzgerald, S. A. Ringel, “Lattice-matched GaP/SiGe virtual substrates for low-dislocation density GaInP/GaAsP/Si solar cells,” Proc. 38th IEEE Photovoltaic Specialists Conference, 000918 (2012).
  44. J. Grandal, T. J. Grassman, A. M. Carlin, M. R. Brenner, B. Galiana, J. A. Carlin, L.-M. Yang, M. J. Mills, S. A. Ringel, “Growth and characterization of InGaAs quantum dots on metamorphic GaAsP templates by molecular beam epitaxy,” Proc. 38th IEEE Photovoltaic Specialists Conference, 001783 (2012).
  45. T. J. Grassman, A. M. Carlin, J. Grandal, C. Ratcliff, L.-M. Yang, M. J. Mills, S. A. Ringel, “Spectrum-optimized Si-based III-V multijunction photovoltaics,” Proc. SPIE 8256: Physics, Simulation, and Photonic Engineering of Photovoltaic Devices, 82560R (2012).
  46. K. Swaminathan, T. J. Grassman, L.-M. Yang, D. Chmielewski, M. J. Mills, S. A. Ringel, “Impact of threading dislocations on metamorphic InxGa1-xAs and InzGa1-zP p-i-n photodetectors on GaAs,” Proc. SPIE 8257: Optical Components and Materials IX, 82571A (2012).
  47. C. Ratcliff, T. J. Grassman, J. A. Carlin, S. A. Ringel, “High temperature step-flow growth of gallium phosphide by molecular beam epitaxy and metalorganic chemical vapor deposition,” Applied Physics Letters 99, 141905 (2011).
  48. K. Swaminathan, T. J. Grassman, L.-M. Yang, Q. Gu, M. J. Mills, S. A. Ringel, “Optically-aligned visible/near-infrared dual-band photodetector materials and devices on GaAs using metamorphic epitaxy,” Journal of Applied Physics 110(6), 063109 (2011).
  49. T. J. Grassman, A. M. Carlin, K. Swaminathan, C. Ratcliff, J. Grandal, L.-M. Yang, M. J. Mills, S. A. Ringel, “Expanding the palette: metamorphic strategies over multiple lattice constant ranges for extending the spectrum of accessible photovoltaic materials,” Proc. 37th IEEE Photovoltaic Specialists Conference, 003375 (2011).
  50. L-M. Yang, K. Swaminathan, T. Grassman, S. Ringel and M. Mills, “Threading Dislocations in Metamorphic In0.20Ga0.80As Grown on GaAs Substrates,” Microscopy and Microanalysis 17(S2), 1652-1653 (2011).
  51. K. Swaminathan, L.-M. Yang, T. J. Grassman, G. Tabares, A. Guzman, A. Hierro, M. J. Mills, S. A. Ringel, “Metamorphic In0.20Ga0.80As p-i-n photodetectors grown on GaAs substrates for near infrared applications,” Optics Express 19(8), 7280 (2011).
  52. T. J. Grassman, M. R. Brenner, M. Gonzalez, A. M. Carlin, R. R. Unocic, R. R. Dehoff, M. J. Mills, S. A. Ringel, “Characterization of metamorphic GaAsP/Si materials and devices for photovoltaic applications,” IEEE Transactions on Electron Devices 57(12), 3361 (2010).
  53. J. S. Lee, S. R. Bishop, T. J. Grassman, A. C. Kummel, “Plasma nitridation of Ge(100) surface studied by scanning tunneling microscopy,” Surface Science 604, 1239 (2010).
  54. T. J. Grassman, A. M. Carlin, S. A. Ringel, “Metamorphic GaAsP and InGaP photovoltaic materials on Si for high-efficiency III-V/Si multijunction solar cells,” Proc. 35th IEEE Photovoltaic Specialists Conference, 002029 (2010).
  55. T. J. Grassman, M. R. Brenner, A. M. Carlin, S. Rajagopalan, R. R. Unocic, R. R. Dehoff, M. J. Mills, H. L. Fraser, S. A. Ringel, “Toward metamorphic multijunction GaAsP/Si photovoltaics grown on optimized GaP/Si virtual substrates using anion-graded GaAsyP1-y buffers,” Proc. 34th IEEE Photovoltaic Specialists Conference, 002016 (2009).
  56. T. J. Grassman, M. R. Brenner, S. Rajagopalan, R. R. Unocic, R. R. Dehoff, M. J. Mills, H. L. Fraser, S. A. Ringel, “Control and elimination of nucleation-related defects in GaP/Si(001) heteroepitaxy,” Applied Physics Letters 94, 232106 (2009).
  57. T. J. Grassman, S. R. Bishop, A. C. Kummel, “Density functional theory study of first-layer adsorption of ZrO2 and HfO2 on Ge(100),” Microelectronic Engineering 86, 249 (2009).
  58. D. L. Feldwinn, J. B. Clemens, J. Shen, S. R. Bishop, T. J. Grassman, A. C. Kummel, R. Droopad, M. Passlack, “Anomalous hybridization in the In-rich InAs(001) reconstruction,” Surface Science 603, 3321 (2009).
  59. N. L. Tran, S. R. Bishop, T. J. Grassman, G. C. Poon, F. I. Bohrer, W. C. Trogler, A. C. Kummel, “NO chemisorptions dynamics on thick FePc and ttbu-FePc films,” Journal of Chemical Physics 130, 174305 (2009).
  60. T. J. Grassman, S. R. Bishop, A. C. Kummel, “An atomic view of Fermi level pinning of Ge(100) by O2,” Surface Science 602, 2373 (2008).
  61. D. L. Winn, T. J. Grassman, A. C. Kummel, “Electronic properties of adsorbates on In0.37Ga0.63As(001)-(2×4),” ECS Transactions 11, 441 (2007).
  62. D. L. Winn, M. J. Hale, T. J. Grassman, J. Z. Sexton, A. C. Kummel, R. Droopad, and M. Passlack, “Electronic properties of adsorbates on GaAs(001)-c(2×8)/(2×4)” Journal of Chemical Physics 127, 134705 (2007).
  63. D. L. Winn, M. J. Hale, T. J. Grassman, A. C. Kummel, R. Droopad, M. Passlack, “Direct and indirect causes of Fermi level pinning at the SiO/GaAs interface,” Journal of Chemical Physics 126, 84703 (2007).
  64. D. L. Winn, T. J. Grassman and A. C. Kummel, “Electronic Properties of Adsorbates on In0.37Ga0.63As(001)-(2×4),” ECS Transactions 11(4), 441 (2007).
  65. M. J. Hale, D. L. Winn, T. J. Grassman, A. C. Kummel, “Chemically resolved scanning tunneling microscopy imaging of Al on p-type Al0.1Ga0.9As(001)-c(2×8)/(2×4),” Journal of Chemical Physics 122, 124702 (2005).
  66. T. J. Grassman, G. C. Poon, A. C. Kummel, “Low coverage spontaneous etching and hyperthermal desorption of aluminum chlorides from Cl2 on Al(111),” Journal of Chemical Physics 121, 9018 (2004).
  67. G. C. Poon, T. J. Grassman, J. C. Gumy, A. C. Kummel, “Direct and precursor-mediated hyperthermal abstractive chemisorption of Cl2/Al(111),” Journal of Chemical Physics 119, 18 (2003).
  68. M. K. Knowles, T. J. Grassman, A. H. Marcus, “Measurement of the dynamic structure function of fluorescently labeled complex fluids by Fourier imaging correlation spectroscopy,” Physical Review Letters 85, 2837 (2000).
  69. T. J. Grassman, M. K. Knowles, A. H. Marcus, “Structure and dynamics of fluorescently labeled complex fluids by Fourier imaging correlation spectroscopy,” Physical Review E 62, 8245 (2000).