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Space-separated quantum cutting with silicon nanocrystals for photovoltaic applications


For optimal energy conversion in photovoltaic devices (electricity to and from light) one important requirement is that the full energy of the photons is used. However, in solar cells, a single electron–hole pair of specific energy is generated when the incoming photon energy is above a certain threshold, with the excess energy being lost to heat. In the so-called quantum-cutting process, a high-energy photon can be divided into two, or more, photons of lower energy. Such manipulation of photon quantum size can then very effectively increase the overall efficiency of a device. In the current work, we demonstrate (space-separated) photon cutting by silicon nanocrystals, in which nearby Er3+ ions and neighbouring nanocrystals are used to detect this effect.

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Figure 1: Space-separated quantum cutting in an erbium–silicon NC system.
Figure 2: Space-separated quantum cutting between silicon NCs.
Figure 3: Nearest-neighbour distance distribution.


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

    Article  ADS  Google Scholar 

  2. Huynh, W. U., Dittmer, J. J. & Alivisatos, A. P. Hybrid nanorod–polymer solar cells. Science 295, 2425–2427 (2002).

    Article  ADS  Google Scholar 

  3. Peumans, P., Uchida, S. & Forrest, S. R. Efficient bulk heterojunction photovoltaic cells using small-molecular-weight organic thin films. Nature 425, 158–162 (2003).

    Article  ADS  Google Scholar 

  4. 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  ADS  Google Scholar 

  5. Shah, A., Torres, P., Tscharner, R., Wyrsch, N. & Keppner, H. Photovoltaic technology: The case for thin-film solar cells. Science 285, 692–698 (1999).

    Article  Google Scholar 

  6. Wegh, R. T., Donker, H., Oskam, K. D. & Meijerink, A. Visible quantum cutting in LiGdF4:Eu3+ through downconversion. Science 283, 663–666 (1999).

    Article  ADS  Google Scholar 

  7. Luque, A., Martí, A. & Nozik, A. J. Solar cells based on quantum dots: Multiple exciton generation in films of electronically coupled PbSe quantum dots. MRS Bull. 32, 236–241 (2007).

    Article  Google Scholar 

  8. Nozik, A. J. Quantum dot solar cells. Physica E 14, 115–120 (2002).

    Article  ADS  Google Scholar 

  9. Schaller, R. D. & Klimov, V. I. High efficiency carrier multiplication in PbSe nanocrystals: implications for solar energy conversion. Phys. Rev. Lett. 92, 186601 (2004).

    Article  ADS  Google Scholar 

  10. Ellingson, R. J. et al. Highly efficient multiple exciton generation in colloidal PbSe and PbS quantum dots. Nano Lett. 5, 865–871 (2005).

    Article  ADS  Google Scholar 

  11. Schaller, R. D., Petruska, M. A. & Klimov, V. I. Effect of electronic structure on carrier multiplication efficiency: Comparative study of PbSe and CdSe nanocrystals. Appl. Phys. Lett. 87, 253102 (2005).

    Article  ADS  Google Scholar 

  12. Murphy, J. E. et al. PbTe colloidal nanocrystals: synthesis, characterization, and multiple exciton generation. J. Am. Chem. Soc. 128, 3241–3247 (2006).

    Article  Google Scholar 

  13. Schaller, R. D., Sykora, M., Pietryga, J. M. & Klimov, V. I. Seven excitons at a cost of one: Redefining the limits for conversion efficiency of photons into charge carriers. Nano Lett. 6, 424–429 (2006).

    Article  ADS  Google Scholar 

  14. Beard, M. C. et al. Multiple exciton generation in colloidal silicon nanocrystals. Nano Lett. 7, 2506–2512 (2007).

    Article  ADS  Google Scholar 

  15. Klimov, V. I., Mikhailovsky, A. A., McBranch, D. W., Leatherdale, C. A. & Bawendi, M. G. Quantization of multiparticle Auger rates in semiconductor quantum dots. Science 287, 1011–1013 (2000).

    Article  ADS  Google Scholar 

  16. Hendry, E. et al. Direct observation of electron-to-hole energy transfer in CdSe quantum dots. Phys. Rev. Lett. 96, 057408 (2006).

    Article  ADS  Google Scholar 

  17. Fujii, M., Yoshida, M., Kanzawa, Y., Hayashi, S. & Yamamoto, K. 1.54 µm photoluminescence of Er3+ doped into SiO2 films containing Si nanocrystals: Evidence for energy transfer from Si nanocrystals to Er3+. Appl. Phys. Lett. 71, 1198–1200 (1997).

    Article  ADS  Google Scholar 

  18. Izeddin, I., Moskalenko, A. S., Yassievich, I. N., Fujii, M. & Gregorkiewicz, T. Nanosecond dynamics of the near-infrared photoluminescence of Er-doped SiO2 sensitized with Si nanocrystals. Phys. Rev. Lett. 97, 207401 (2006).

    Article  ADS  Google Scholar 

  19. Polman, A. Erbium as a probe of everything? Physica B 300, 78–90 (2001).

    Article  ADS  Google Scholar 

  20. Shabaev, A., Efros, A. L. & Nozik, A. J. Multiexciton generation by a single photon in nanocrystals. Nano Lett. 6, 2856–2863 (2006).

    Article  ADS  Google Scholar 

  21. Schaller, R. D., Agranovich, V. M. & Klimov V. I. High-efficiency carrier multiplication through direct photogeneration of multi-excitons via virtual single-exciton states. Nature Phys. 1, 189–194 (2005).

    Article  ADS  Google Scholar 

  22. Rupasov, V. I. & Klimov, V. I. Carrier multiplication in semiconductor nanocrystals via intraband optical transitions involving virtual biexciton states. Phys. Rev. B 76, 125321 (2007).

    Article  ADS  Google Scholar 

  23. Califano, M., Zunger, A. & Franceschetti, A. Direct carrier multiplication due to inverse Auger scattering in CdSe quantum dots. Appl. Phys. Lett. 84, 2409–2411 (2004).

    Article  ADS  Google Scholar 

  24. Mihalcescu, I. et al. Saturation and voltage quenching of porous-silicon luminescence and the importance of the Auger effect. Phys. Rev. B 51, 17605–17613 (1995).

    Article  ADS  Google Scholar 

  25. Trojanek, F., Neudert, K., Brittner, M. & Maly, P. Picosecond photoluminescence and transient absorption in silicon nanocrystals. Phys. Rev. B 72, 075365 (2005).

    Article  ADS  Google Scholar 

  26. Allan, G. & Delerue, C. Role of impact ionization in multiple exciton generation in PbSe nanocrystals. Phys. Rev. B 73, 205423 (2006).

    Article  ADS  Google Scholar 

  27. Kagan, C. R., Murray, C. B. & Bawendi, M. G. Long-range resonance transfer of electronic excitations in close-packed CdSe quantum-dot solids. Phys. Rev. B 54, 8633–8643 (1996).

    Article  ADS  Google Scholar 

  28. Nanda, K. K., Kruis, F. E. & Fissan, H. Energy levels in embedded semiconductor nanoparticles and nanowires. Nano Lett. 1, 605–611 (2001).

    Article  ADS  Google Scholar 

  29. Murray, C. B., Norris, D. J. & Bawendi, M. G. Synthesis and characterization of nearly monodisperse CdE (E = S, Se, Te) semiconductor nanocrystallites. J. Am. Chem. Soc. 115, 8706–8715 (1993).

    Article  Google Scholar 

  30. Hanna, M. C. & Nozik, A. J. Solar conversion efficiency of photovoltaic and photoelectrolysis cells with carrier multiplication absorbers. J. Appl. Phys. 100, 074510 (2006).

    Article  ADS  Google Scholar 

  31. Trupke, T., Green, M. A. and Würfel, P. Improving solar cell efficiencies by down-conversion of high-energy photons. J. Appl. Phys. 92, 1668–1674 (2002).

    Article  ADS  Google Scholar 

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The authors acknowledge the contribution of M. Fujii, Kobe University, for sample preparation and characterization, and R. Sprik, W.J. Buma and M. de Groot, University of Amsterdam, for absorption and dye laser PL measurements. P.S. acknowledges the financial support of Stichting voor Fundamenteel Onderzoek Materie (FOM) during his sabbatical at the Van der Waals–Zeeman Institute.

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Correspondence to D. Timmerman.

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Timmerman, D., Izeddin, I., Stallinga, P. et al. Space-separated quantum cutting with silicon nanocrystals for photovoltaic applications. Nature Photon 2, 105–109 (2008).

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