Skip to main content

Photovoltaic Energy Conversion

  • Chapter
  • First Online:
Organic Solar Cells

Part of the book series: Springer Series in Materials Science ((SSMATERIALS,volume 208))

Abstract

This chapter provides an introduction to the basic principles of solar energy conversion including its thermodynamic limits. We discuss the optical and electrical requirements for an ideal photovoltaic device and show examples of possible realizations based on semiconductors. To recall the basics, a brief review on semiconductor physics with emphasis on the p-n junction is given. We discuss the role of the electrochemical potential as driving force for the conversion of sunlight into electricity. We conclude with estimations on the maximum power-conversion efficiency for a single band-edge absorber and introduce approaches for achieving it or even going beyond it. Readers without any background in solid state physics might consider consulting an introductory textbook while reading this chapter. If the reader comes to the conclusion that his/her background in physics is not sufficient, he might consider to skip this chapter and directly start with Chap. 3, as a detailed understanding of thermodynamics is not required to follow most of the elaborations on the working principle of organic solar cells in subsequent chapters. The reader interested in the fundamental laws of solar energy conversion should follow this chapter and be able to answer the following questions afterwards: (a) What is the thermodynamic limit of solar-thermal energy conversion with a device located on the earth surface? What is the role of entropy? (b) Why is the power-conversion efficiency of a solar cell based on a single semiconductor limited to 33 %? What tradeoffs have to be made? (c) Where is the “maximum” of the solar spectrum located? What are possibilities of expressing spectra (e.g. from the sun) considering energy versus wavelength or photon fluxes versus intensity fluxes (irradiance)? (d) What are the main optical and electrical properties of semiconductors and how can they be derived? (e) What are the relations between Fermi levels and charge carrier densities? (f) What are the driving forces for the movement of charge carriers? What is the concept of quasi-Fermi levels? (g) What is the effect of recombination on the photovoltage of a solar cell? Which loss processes are unavoidable? (h) How does a p-n junction solar cell work? Are there alternative architectures? (i) What are the basic requirements for a solar cell? Consider the role of selective contacts and the built-in electric field. (j) Why should a good solar cell show a high electroluminescence quantum yield, i.e. large emission? (k) What are the main concepts for overcoming the so-called Shockley-Queisser limit?

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 129.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 169.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 169.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

References

  1. ASTM Reference Spectra: http://rredc.nrel.gov/solar/spectra/am1.5/ASTMG173/ASTMG173.html

  2. DWD: Globalstrahlung in der Bundesrepublik Deutschland. http://www.dwd.de/bvbw/appmanager/bvbw/dwdwwwDesktop (2010)

  3. Meteonorm: Global irradiance. http://meteonorm.com/fileadmin/user_upload/maps/world_beam_8100.png. Accessed on 15 Aug 2011

  4. Würfel, P.: Physics of Solar Cells: From Basic Principles to Advanced Concepts. Wiley-VCH, Weinheim (2009)

    Google Scholar 

  5. Würfel, P.: Thermodynamic limitations to solar energy conversion. Phys. E 14, 18–26 (2002)

    Article  Google Scholar 

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

    Article  Google Scholar 

  7. Sze, S.M.: Physics of Semiconductor Devices, 2nd edn. Wiley, New York (1981)

    Google Scholar 

  8. Kittel, C.: Introduction to Solid State Physics, 8th edn. Wiley, New York (2004)

    Google Scholar 

  9. Jacoboni, C.: Theory of Electron Transport in Semiconductors : A Pathway from Elementary Physics to Nonequilibrium Green Functions. Springer, Berlin, Heidelberg (2010)

    Book  Google Scholar 

  10. Würfel, P.: The chemical potential of radiation. J. Phys. C: Solid State Phys. 15, 3967–3985 (1982)

    Article  Google Scholar 

  11. Tiedje, T., Yablonovitch, E.: Limiting efficiency of silicon solar cells. Electron Devices IEEE 31, 711–716 (1984)

    Google Scholar 

  12. Shockley, W., Read, W.: Statistics of the recombinations of holes and electrons. Phys. Rev. 87, 835–842 (1952)

    Article  Google Scholar 

  13. Bloch, F.: Uber die Quantenmechanik der Elekronen in Kristallgittern. Zeitschrift für Physik A 52, 555–600 (1929)

    Google Scholar 

  14. Leo, K., Bolivar, P.H., Bruggemann, F.: Observation of Bloch oscillations in a semiconductor superlattice. Solid State Commun. 84, 943–946 (1992)

    Article  Google Scholar 

  15. Hauser, J.R., Dunbar, P.M.: Performance limitations of silicon solar cells. IEEE Trans. Electron Devices 24, 305–321 (1977)

    Article  Google Scholar 

  16. Fossum, J.G., Burgess, E.L.: High-efficiency p+-n-n+ back-surface-field silicon solar cells. Appl. Phys. Lett. 33, 238–240 (1978)

    Article  Google Scholar 

  17. Kerr, M.J., Cueva, A., Patrick, P.: Limiting efficiency of crystalline silicon solar cells due to Coulomb-enhanced Auger recombination. Prog. Photovoltaics Res. Appl. 11, 97–104 (2003)

    Article  Google Scholar 

  18. O’regan, B., Grätzel, M.: A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature 353, 737–740 (1991)

    Article  Google Scholar 

  19. Grätzel, M.: Recent advances in sensitized mesoscopic solar cells. Acc. Chem. Res. 42, 1788–1798 (2009)

    Article  Google Scholar 

  20. De Wolf, S., Descoeudres, A., Holman, Z. C., Ballif, C.: High-efficiency silicon heterojunction solar cells: a review. Green 2, 7–24 (2012)

    Google Scholar 

  21. Descoeudres, A., Holman, Z.C., Barraud, L., Morel, S., De Wolf, S., Ballif, C.:>21 % efficient silicon heterojunction solar cells on n- and p-type wafers compared. IEEE Journal of Photovoltaics 3, 83–89 (2013)

    Article  Google Scholar 

  22. Maennig, B., Drechsel, J., Gebeyehu, D., Simon, P., Kozlowski, F., Werner, A., Li, F., Grundmann, S., Sonntag, S., Koch, M., Leo, K., Pfeiffer, M., Hoppe, H., Meissner, D., Sariciftci, N.S., Riedel, I., Dyakonov, V., Parisi, J.: Organic p-i-n solar cells. Appl. Phys. A 79, 1–14 (2004)

    Article  Google Scholar 

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

    Article  Google Scholar 

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

    Article  Google Scholar 

  25. Green, M.A., Emery, K., Hishikawa, Y., Warta, W., Dunlop, E.D.: Solar cell efficiency tables (version 41). Prog. Photovoltaics Res. Appl. 21, 1–11 (2013)

    Google Scholar 

  26. Yablonovitch, Eli: Statistical ray optics. J. Opt. Soc. Am. 72, 899 (1982)

    Article  Google Scholar 

  27. Miller, O.D., Yablonovitch, E., Kurtz, S.R.: Strong internal and external luminescence as solar cells approach the Shockley-Queisser limit. IEEE Journal of Photovoltaics 2(3), 303–311 (2012)

    Google Scholar 

  28. Tang, Z., Elfwing, A., Bergqvist, J., Tress, W., Inganäs, O.: Light trapping with dielectric scatterers in single- and tandem-junction organic solar cells. Adv. Energy Mater. 3, 1606–1613 (2013)

    Google Scholar 

  29. Green, M.A., Emery, K., Hishikawa, Y., Warta, W., Dunlop, E.D.: Solar cell efficiency tables (version 40). Prog. Photovoltaics Res. Appl. 20, 606–614 (2012)

    Google Scholar 

  30. Green, M.A.: Third generation photovoltaics: ultra-high conversion efficiency at low cost. Prog. Photovoltaics Res. Appl. 9, 123–135 (2001)

    Article  Google Scholar 

  31. Lewis, N.S.: Toward cost-effective solar energy use. Science 315, 798–801 (2007)

    Article  Google Scholar 

  32. Service, R.F.: Solar energy. Can the upstarts top silicon? Science 319, 718–720 (2008)

    Google Scholar 

  33. Vos, A.D.: Detailed balance limit of the efficiency of tandem solar cells. J. Phys. D: Appl. Phys. 13, 839–846 (1980)

    Article  Google Scholar 

  34. Tandem solar cell by Heliatek with an efficiency of 12.0 % on an area of 1.1 square centimeters, certified at SGS. Press release (2013)

    Google Scholar 

  35. Fundamental (high-level) introduction on solar cell physics, which some sections of this chapter are based on: Würfel, P.: Physics of Solar Cells: From Basic Principles to Advanced Concepts. Wiley-VCH, Weinheim (2009)

    Google Scholar 

  36. Clear textbook on solid state physics: Kittel, C.: Introduction to Solid State Physics, 8th edn. Wiley, New york (2004)

    Google Scholar 

  37. Good introductory textbook on physics of solar cells: Nelson, J.: The Physics of Solar Cells. World Scientific Pub Co, Singapore (2003)

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Wolfgang Tress .

Rights and permissions

Reprints and permissions

Copyright information

© 2014 Springer International Publishing Switzerland

About this chapter

Cite this chapter

Tress, W. (2014). Photovoltaic Energy Conversion. In: Organic Solar Cells. Springer Series in Materials Science, vol 208. Springer, Cham. https://doi.org/10.1007/978-3-319-10097-5_2

Download citation

Publish with us

Policies and ethics