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Six-junction III–V solar cells with 47.1% conversion efficiency under 143 Suns concentration

Nature Energy volume 5, pages 326–335 (2020)Cite this article

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Abstract

Single-junction flat-plate terrestrial solar cells are fundamentally limited to about 30% solar-to-electricity conversion efficiency, but multiple junctions and concentrated light make much higher efficiencies practically achievable. Until now, four-junction III–V concentrator solar cells have demonstrated the highest solar conversion efficiencies. Here, we demonstrate 47.1% solar conversion efficiency using a monolithic, series-connected, six-junction inverted metamorphic structure operated under the direct spectrum at 143 Suns concentration. When tuned to the global spectrum, a variation of this structure achieves a 1-Sun global efficiency of 39.2%. Nearly optimal bandgaps for six junctions were fabricated using alloys of III–V semiconductors. To develop these junctions, it was necessary to minimize threading dislocations in lattice-mismatched III–V alloys, prevent phase segregation in metastable quaternary III–V alloys and understand dopant diffusion in complex structures. Further reduction of the series resistance within this structure could realistically enable efficiencies over 50%.

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Fig. 1: Description of the 6J IMM solar cell structure.
Fig. 2: Process flow of the 6J IMM solar cell.
Fig. 3: Challenge of zinc diffusion in the fourth and fifth junctions.
Fig. 4: One-Sun performance of 6J IMM solar cells.
Fig. 5: High concentration performance of 6J IMM solar cells.
Fig. 6: Subcell analysis of the 6J IMM solar cell.

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All data generated or analysed during this study are included in the published aticle and its Supplementary Information and Source Data files.

References

  1. Shockley, W. & Queisser, H. J. Detailed balance limit of efficiency of p-n junction solar cells. J. Appl. Phys. 32, 510–519 (1961).

    Google Scholar 

  2. Steiner, M. A. et al. Optical enhancement of the open-circuit voltage in high quality GaAs solar cells. J. Appl. Phys. 113, 123109 (2013).

    Google Scholar 

  3. Miller, O. D., Yablonovitch, E. & Kurtz, S. R. Strong internal and external luminescence as solar cells approach the Shockley–Queisser limit. IEEE J. Photovolt. 2, 303–311 (2012).

    Google Scholar 

  4. Henry, C. H. Limiting efficiencies of ideal single and multiple energy gap terrestrial solar cells. J. Appl. Phys. 51, 4494–4500 (1980).

    Google Scholar 

  5. Marti, A. & Araujo, G. L. Limiting efficiencies for photovoltaic energy conversion in multigap systems. Sol. Energ. Mater. Sol. Cells 43, 203–222 (1996).

    Google Scholar 

  6. McMahon, W. E., Friedman, D. J. & Geisz, J. F. Multijunction solar cell design revisited: disruption of current-matching by atmospheric absorption bands. Prog. Photovolt: Res. Appl. 25, 850–860 (2017).

    Google Scholar 

  7. Green, M. A. Radiative efficiency of state-of-the-art photovoltaic cells. Prog. Photovolt: Res. Appl. 20, 472–476 (2012).

    Google Scholar 

  8. Rau, U. Reciprocity relation between photovoltaic quantum efficiency and electroluminescent emission of solar cells. Phys. Rev. B 76, 085303 (2007).

    Google Scholar 

  9. Onabe, K. Calculation of miscibility gap in quaternary InGaPAs with strictly regular solution approximation. Jpn. J. Appl. Phys. 21, 797–798 (1982).

    Google Scholar 

  10. Geisz, J. F. et al. 40.8% efficient inverted triple-junction solar cell with two independently metamorphic junctions. Appl. Phys. Lett. 93, 123505 (2008).

    Google Scholar 

  11. Guter, W. et al. Current-matched triple-junction solar cell reaching 41.1% conversion efficiency under concentrated sunlight. Appl. Phys. Lett. 94, 223504 (2009).

    Google Scholar 

  12. France, R. M., Dimroth, F., Grassman, T. J. & King, R. R. Metamorphic epitaxy for multijunction solar cells. MRS Bull. 41, 202–209 (2016).

    Google Scholar 

  13. Stringfellow, G. Spinodal decomposition and clustering in III/V alloys. J. Electron. Mater. 11, 903–918 (1982).

    Google Scholar 

  14. Stringfellow, G. B. The importance of lattice mismatch in the growth of GaxIn1-xP epitaxial crystals. J. Appl. Phys. 43, 3455–3460 (1972).

    Google Scholar 

  15. Oshima, R., France, R. M., Geisz, J. F., Norman, A. G. & Steiner, M. A. Growth of lattice-mismatched GaInAsP grown on vicinal GaAs(001) substrates within the miscibility gap for solar cells. J. Cryst. Growth 458, 1–7 (2017).

    Google Scholar 

  16. Dimroth, F. et al. Four-junction wafer-bonded concentrator solar cells. IEEE J. Photovolt. 6, 343–349 (2016).

    Google Scholar 

  17. Wanlass, M. W. et al. Monolithic ultra-thin GaInP/GaAs/GaInAs tandem solar cells. In 4th World Conference on Photovoltaic Energy Conversion 729–732 (IEEE, 2006); https://doi.org/10.1109/WCPEC.2006.279559

  18. France, R. M. et al. Design flexibility of ultra-high efficiency four-junction inverted metamorphic solar cells. IEEE J. Photovolt. 6, 578–583 (2016).

    Google Scholar 

  19. Young, J. L. et al. Direct solar-to-hydrogen conversion via inverted metamorphic multi-junction semiconductor architectures. Nat. Energy 2, 17028 (2017).

    Google Scholar 

  20. Omair, Z. et al. Ultraefficient thermophotovoltaic power conversion by band-edge spectral filtering. PNAS 116, 15356–15361 (2019).

    Google Scholar 

  21. Garcia, I., Geisz, J. F., France, R. M., Steiner, M. A. & Friedman, D. J. Component integration strategies in metamorphic 4-junction III-V concentrator solar cells. AIP Conf. Proc. 1616, 41–44 (2014).

    Google Scholar 

  22. Geisz, J. F. et al. Building a six-junction inverted metamorphic concentrator solar cell. IEEE J. Photovolt. 8, 626–632 (2018).

    Google Scholar 

  23. Garcia, I. et al. Metamorphic Ga0.76In0.24As/GaAs0.75Sb0.25 tunnel junctions grown on GaAs substrates. J. Appl. Phys. 116, 074508 (2014).

    Google Scholar 

  24. Matthews, J. W. & Blakeslee, A. E. Defects in epitaxial multilayers I. Misfit dislocations. J. Cryst. Growth 27, 118–125 (1974).

    Google Scholar 

  25. Andre, C. L. et al. Impact of dislocation densities on n +/p and p +/n junction GaAs diodes and solar cells on SiGe virtual substrates. J. Appl. Phys. 98, 014502 (2005).

    Google Scholar 

  26. Schulte, K. L., France, R. M. & Geisz, J. F. Highly transparent compositionally graded buffers for new metamorphic multijunction solar cell designs. IEEE J. Photovolt. 7, 347–353 (2017).

    Google Scholar 

  27. Quitoriano, N. J. & Fitzgerald, E. A. Relaxed, high-quality InP on GaAs by using InGaAs and InGaP graded buffers to avoid phase separation. J. Appl. Phys. 102, 033511 (2007).

    Google Scholar 

  28. McMahon, W. E. et al. Ordering-enhanced dislocation glide in III-V alloys. J. Appl. Phys. 114, 203506 (2013).

    Google Scholar 

  29. Suzuki, T. & Gomyo, A. Sublattice ordering in GaInP and AlGaInP: effects of substrate orientations. J. Cryst. Growth 99, 60–67 (1990).

    Google Scholar 

  30. Geisz, J. F. et al. Six-junction concentrator solar cells. AIP Conf. Proc. 2012, 040004 (2018).

    Google Scholar 

  31. Andreev, V. M., Grilikhes, V. A. & Rumyantsev, V. D. Photovoltaic Conversion of Concentrated Sunlight (Wiley, 1997).

  32. Luque, A. & Hegedus, S. Handbook of Photovoltaic Science and Engineering (Wiley, 2007).

  33. Fraas, L. & Partain, L. Solar Cells and Their Applications (Wiley, 2010).

  34. Badescu, V. Maximum concentration ratio of direct solar radiation. Appl. Opt. 32, 2187–2189 (1993).

    Google Scholar 

  35. Jones-Albertus, R. E. & Sheldon, M. J. Reverse heterojunctions for solar cells. US patent 2013/0263923 A1 (2013).

  36. Steiner, M. A. et al. Reverse heterojunction (Al)GaInP solar cells for improved efficiency at concentration. IEEE J. Photovolt. 10, 487–494 (2020).

    Google Scholar 

  37. Saive, R. et al. Effectively transparent front contacts for optoelectronic devices. Adv. Opt. Mater. 4, 1470–1474 (2016).

    Google Scholar 

  38. Ward, J. S. et al. High aspect ratio electrodeposited Ni/Au contacts for GaAs-based III-V concentrator solar cells. Prog. Photovolt: Res. Appl. 23, 646–653 (2015).

    Google Scholar 

  39. Geisz, J. F. et al. Pathway to 50% efficient inverted metamorphic concentrator solar cells. AIP Conf. Proc. 1881, 040003 (2017).

    Google Scholar 

  40. Schulte, K. L., Steiner, M. A., Young, M. R. & Geisz, J. F. Internal resistive barriers related to Zn diffusion during the growth of inverted metamorphic multi-junction solar cells. IEEE J. Photovolt. 9, 167–173 (2019).

    Google Scholar 

  41. Deppe, D. G. Thermodynamic explanation to the enhanced diffusion of base dopant in AlGaAs-GaAs npn bipolar transistors. Appl. Phys. Lett. 56, 370–372 (1990).

    Google Scholar 

  42. Takamoto, T. et al. Mechanism of Zn and Si diffusion from a highly doped tunnel junction for InGaP/GaAs tandem solar cells. J. Appl. Phys. 85, 1481–1486 (1999).

    Google Scholar 

  43. Galiana, B., Rey-Stolle, I., Baudrit, M., García, I. & Algora, C. A comparative study of BSF layers for GaAs-based single-junction or multijunction concentrator solar cells. Semicond. Sci. Technol. 21, 1387–1392 (2006).

    Google Scholar 

  44. Green, M. A. et al. Solar cell efficiency tables (version 54). Prog. Photovolt: Res. Appl. 27, 565–575 (2019).

    Google Scholar 

  45. Chiu, P. T. et al. Direct semiconductor bonded 5J cell for space and terrestrial applications. IEEE J. Photovolt. 4, 493–497 (2014).

    Google Scholar 

  46. Geisz, J. F. et al. Generalized optoelectronic model of series-connected multijunction solar cells. IEEE J. Photovolt. 5, 1827–1839 (2015).

    Google Scholar 

  47. Roensch, S., Hoheisel, R., Dimroth, F. & Bett, A. W. Subcell I-V characteristic analysis of GaInP/GaInAs/Ge solar cells using electroluminescence measurements. Appl. Phys. Lett. 98, 251113 (2011).

    Google Scholar 

  48. Kirchartz, T. et al. Internal voltages in GaInP/GaInAs/Ge multijunction solar cells determined by electroluminescence measurements. Appl. Phys. Lett. 92, 123502 (2008).

    Google Scholar 

  49. Geisz, J. F., Steiner, M. A., Garcia, I., Kurtz, S. R. & Friedman, D. J. Enhanced external radiative efficiency for 20.8% efficient single-junction GaInP solar cells. Appl. Phys. Lett. 103, 041118 (2013).

    Google Scholar 

  50. Geisz, J. F., Levander, A. X., Norman, A. G., Jones, K. M. & Romero, M. J. In situ stress measurement for MOVPE growth of high efficiency lattice-mismatched solar cells. J. Cryst. Growth 310, 2339–2344 (2008).

    Google Scholar 

  51. France, R. M., McMahon, W. E., Kang, J., Steiner, M. A. & Geisz, J. F. In situ measurement of CuPt alloy ordering using strain anisotropy. J. Appl. Phys. 115, 053502 (2014).

    Google Scholar 

  52. Breiland, W. G. & Killeen, K. P. A virtual interface method for extracting growth rates and high temperature optical constants from thin semiconductor films using in situ normal incidence reflectance. J. Appl. Phys. 78, 6726–6736 (1995).

    Google Scholar 

  53. France, R. M. et al. Reduction of crosshatch roughness and threading dislocation density in metamorphic GaInP buffers and GaInAs solar cells. J. Appl. Phys. 111, 103528 (2012).

    Google Scholar 

  54. Garcia, I., France, R. M., Geisz, J. F. & Simon, J. Thin, high quality GaInP compositionally graded buffer layers grown at high growth rates for metamorphic III-V solar cell applications. J. Cryst. Growth 393, 64–69 (2014).

    Google Scholar 

  55. Schulte, K. L. et al. Reduced dislocation density in GaxIn1−xP compositionally graded buffer layers through engineered glide plane switch. J. Cryst. Growth 464, 20–27 (2017).

    Google Scholar 

  56. Schermer, J. J. et al. High rate epitaxial lift-off of InGaP films from GaAs substrates. Appl. Phys. Lett. 76, 2131–2133 (2000).

    Google Scholar 

  57. Tatavarti, R. et al. Lightweight, low cost GaAs solar cells on 4″ epitaxial liftoff (ELO) wafers. In 33rd Photovoltaic Specialists Conference 1–4 (IEEE, 2008); https://doi.org/10.1109/PVSC.2008.4922900

  58. Bedell, S. W. et al. Kerf-less removal of Si, Ge, and III–V layers by controlled spalling to enable low-cost PV technologies. IEEE J. Photovolt. 2, 141–147 (2012).

    Google Scholar 

  59. France, R. M. et al. Quadruple junction inverted metamorphic concentrator devices. IEEE J. Photovolt. 5, 432–437 (2015).

    Google Scholar 

  60. Barrigón, E., Espinet, P., Contreras, Y. & Rey-Stolle, I. Implications of low breakdown voltage of component subcells on external quantum efficiency measurements of multijunction solar cells. Prog. Photovolt: Res. Appl. 23, 1597–1607 (2015).

    Google Scholar 

  61. Steiner, M. A. et al. Measuring IV curves and subcell photocurrents in the presence of luminescent coupling. IEEE J. Photovolt. 3, 879–887 (2013).

    Google Scholar 

  62. Moriarty, T., Jablonski, J. & Emery, K. Algorithm for building a simulator spectrum for NREL one-sun multi-source simulator. In 38th Photovoltaic Specialists Conference (IEEE, 2012); https://doi.org/10.1109/PVSC.2012.6317838

  63. Moriarty, T., France, R. & Steiner, M. Rapid, enhanced IV characterization of multi-junction PV devices under one Sun at NREL. In 42nd IEEE Photovoltaic Specialists Conference (IEEE, 2015); https://doi.org/10.1109/PVSC.2015.7355845

  64. Osterwald, C. R., Wanlass, M. W., Moriarty, T., Steiner, M. A. & Emery, K. A. Concentrator cell efficiency measurement errors caused by unfiltered xenon flash solar simulators. AIP Conf. Proc. 1616, 149–153 (2014).

    Google Scholar 

  65. Osterwald, C. R., Emery, K. A., Myers, D. R. & Hart, R. E. Primary reference cell calibrations at SERI: history and methods. In 21st IEEE Photovoltaic Specialists Conference 1062 (IEEE, 1990); https://doi.org/10.1109/PVSC.1990.111780

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Acknowledgements

The authors thank W. Olavarría and M. Young for cell fabrication. I. Garcia, N. Jain and E. Perl developed the initial components of the 6J IMM as referenced. We thank D. Friedman for managerial support and helpful discussions. J. Olson, S. Kurtz and M. Wanlass laid the groundwork for all multijunction solar cells at NREL. Thanks to J. K. Geisz for help with photography and A. Hicks for graphics design. This work was authored by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the US Department of Energy (DOE) under Contract no. DE-AC36-08GO28308. Funding was provided by the US Department of Energy Efficiency and Renewable Energy Solar Energy Technologies Office under Agreement Number 30293. The views expressed herein do not necessarily represent the views of the DOE or the US Government.

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Authors and Affiliations

  1. National Renewable Energy Laboratory (NREL), Golden, CO, USA

    John F. Geisz, Ryan M. France, Kevin L. Schulte, Myles A. Steiner, Andrew G. Norman, Harvey L. Guthrey, Matthew R. Young, Tao Song & Thomas Moriarty

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  1. John F. Geisz
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Contributions

The 6J IMM epilayer structure on 2°B was designed by R.F. following initial designs by K.S. and M.S. on 6°A; T.S. of the independent cell performance team at NREL verified initial performance measurements from R.F. and J.G; 6J equipment development and junction analysis were performed by J.G.; uncertainty analysis was performed by T.M; A.N. performed TEM; H.G performed CL; M.Y. performed SIMS; J.G. and R.F. wrote the manuscript and all other authors provided feedback. The project was led by J.G.

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Correspondence to John F. Geisz.

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Geisz, J.F., France, R.M., Schulte, K.L. et al. Six-junction III–V solar cells with 47.1% conversion efficiency under 143 Suns concentration. Nat Energy 5, 326–335 (2020). https://doi.org/10.1038/s41560-020-0598-5

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