InAs and InP Quantum Dot Molecules and their Potentials for Photovoltaic Applications


Self-assembled InAs and InP quantum dot molecules (QDMs) are grown on GaAs substrates using different molecular beam epitaxial (MBE) growth techniques. The structural and optical properties of the two types of QDMs are then compared and reported. Multi-stack high-density (1012 cm-2) InAs QDMs are grown and when inserted into GaAlAs/GaAs heterostructure results in high-efficiency solar cells. As an alternative to InAs, InP QDMs are grown by droplet epitaxy of In and annealing under P2 pressure. While the number of quantum dots per QDM in the case of InP is in the range of 10 to 12 dots, those in the case of InAs can be smaller or much larger depending on exact growth parameters prior to QD growth. Photoluminescence (PL) measurements show that while InAs QDMs provide room-temperature optical output that peaks at 1.1 eV, InP QDMs have no PL output, possibly due to crystal defects created by low-temperature processing associated with droplet epitaxy. Discussion on the practicality of our QDMs as material for intermediate band solar cells is also provided.

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  1. 1.

    M.Y. Feteha, G.M. Eldallal, Renewable Energy 28, 1097 (2003).

    CAS  Article  Google Scholar 

  2. 2.

    M. Mazzer, K.W.J. Bamham, I.M. Ballard, A. Bessiere, A. Ioannindes, D.C. Johnson, M.C. Lynch, T.N.D. Tibbits, J.S. Roberts, G. Hill, C. Calder, Thin solid films 511–512, 76 (2006).

  3. 3.

    A.W. Bett, R. Adelhelm, C. Agert, R. Beckert, F. Dimroth, U. Schubert, Solar Energy Materials & Solar cells 66, 541 (2001).

    CAS  Article  Google Scholar 

  4. 4.

    G.S. Kinsey, R. A. Sherif, H. L. Cotal, P. Pien, R. R.King, E. L. Labios, K. F. Wan, M. Haddad, J. M. Lacey, C. M. Fetzer, N. H. Karam, P. Verlinden, J. Lasich, presented at the 4th WCPEC, Hawaii, 2006.

  5. 5.

    F. Dimroth, G. Pehavz, U. Wittstadt, B. Hacker, A. Bett, presented at the 4th WCPEC, Hawaii, 2006.

  6. 6.

    R. A. Sherif, R. R. King, G. S. Kinsey, H. L. Cotal, C. M. Fetzer, P. Pien, P. Hebert, J. Lacey, A.Paredes, G. Glem, R.Brandt, T. Cavicchi, J.Peacock, N. Karam, presented at the 21st European PVSEC, Dresden, Germany, 2006.

  7. 7.

    C. Algora, I. Rey-Stolle, B. Galiana, J. R. Goonzalez, M. Baudrit, I. Garcia, III-Vs Review 18, 40 (2005).

    Google Scholar 

  8. 8.

    T. Markvart, Solar Electricity, 2nd ed. (John Willy & Sons Publishers, Chichester, 2000) p.187.

  9. 9.

    T. Takamoto, M. Yamaguchi, S. J. Taylor, M.Yang, E. Ikeda, H.Kurita, Solar Energy Material & Solar cells 58, 265 (1999).

    CAS  Article  Google Scholar 

  10. 10.

    A. Cheknane, H.S. Hilal, J.P. Charles, B. Benyoucef, G. Campet, Solid State Sciences 8, 556 (2006).

    CAS  Article  Google Scholar 

  11. 11.

    J. Nelson, The Physics of Solar Cells, 1st ed. (Imperial College Press Publishers, London, 2003) p.179.

  12. 12.

    M. Yamakuchi, Physica E 14, 84 (2002).

    Article  Google Scholar 

  13. 13.

    M. Yamakuchi, T. Takamoto, K. Araki, Solar Energy Materials & Solar cells 90, 3068 (2006).

    Article  Google Scholar 

  14. 14.

    M.Yamaguchi, T. Takamoto, K. Araki, N. Ekins-Daukes, Solar Energy 79, 78 (2005).

    CAS  Article  Google Scholar 

  15. 15.

    K. Eberl, M.O. Lipinski, Y.M. Manz, W. Winter, N.Y. Jin-Phillipp, O.G. Schmidt, Physica E 9, 164 (2001).

    CAS  Article  Google Scholar 

  16. 16.

    E. Finkman, S. Maimon, V. Immer, G. Bahir, S.E. Schacham, O. Gauthier-Lafaye, S. Herriotc, F.H. Julien, M. Gendry, J. Brault, Physica E 7, 139 (2000).

    CAS  Article  Google Scholar 

  17. 17.

    Y. Okada, N. Shiotsuka, H. Komiyama, K. Akahane, N. Ohtani, presented at the 20th European PVSEC, Barcelona, Spain, 2005.

  18. 18.

    S. Suraprapapich, S. Kanjanachuchai, S. Thainoi, S. Panyakeow, J. Microlith., Microfab., Microsyst. 5, 011008 (2006).

    Google Scholar 

  19. 19.

    S. Ruangdet, S. Thainoi, S. Kanjanachuchai, S. Panyakeow, presented at the 4th WCPEC, Hawaii, 2006.

  20. 20.

    S. Ruangdet, S. Thainoi, S. Kanjanachuchai, S. Panyakeow, presented at the 21st European PVSEC, Dresden, Germany, 2006.

  21. 21.

    L.Cuadra, A. Marti, A.Luque. Thin solid films 451–452, 593–599 (2004).

  22. 22.

    A. Kurtenbach, K. Eberl, T. Shitara, Appl. Phys. Lett. 66, 361 (1995).

    CAS  Article  Google Scholar 

  23. 23.

    A. Moritz, R. Wirth, A. Hangleiter, A. Kurtenbach, K. Eberl, Appl. Phys. Lett. 69, 212 (1996).

    CAS  Article  Google Scholar 

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Correspondence to Wipakorn Jevasuwan.

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Jevasuwan, W., Thainoi, S., Kanjanachuchai, S. et al. InAs and InP Quantum Dot Molecules and their Potentials for Photovoltaic Applications. MRS Online Proceedings Library 959, 1718 (2006).

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  • quantum dot molecules
  • molecular beam epitaxy
  • photovoltaic
  • droplet epitaxy