Abstract
The exciton confinement effect in quantum dots at the surface of SiO2 spheres and the percolation phase transition in films based on a mixture of pure SiO2 spheres and spheres covered by CdS quantum dots (SiO2/CdS nanoparticles) are studied. It is found that, due to the high surface energy of spheres, the quantum dots deposited onto their surface are distorted, which modifies the exciton confinement effect: the effect is retained only in one direction, the direction normal to the surface of the spheres. As a result, the energy of the exciton ground state exhibits a complex dependence on both the quantum-dot radius and sphere size. In the optical spectra of films based on this mixture, the clustering of small-sized nanoparticles and then, at a critical concentration of nanoparticles of ~60%, the formation of a percolation cluster are detected for the first time. The critical concentration is twice higher than the corresponding quantity given by the model of geometrical “colored percolation”, which is a consequence of interaction between submicrometer nanoparticles. The relation between the basic parameters of the percolation transition, such as the film porosity, coordination number, and the quantity defining the number of particles in the percolation cluster, is obtained and analyzed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Nanocrystal Quantum Dots, Ed. by V. I. Klimov (CRC Press, Taylor Francis Group, London, New York, 2010).
Semiconductor Nanocrystals: From Basic Principles to Applications, Ed. by A. L. Efros, D. L. Lockwood, and L. Tsybeskov (Springer Science+Business Media, New York, 2003).
R. G. Chaudhuri and S. Paria, Chem. Rev. 112, 2373 (2012).
A. L. Rogach, D. Nagesha, J. W. Ostrander, M. Giersig, and N. A. Kotov, Chem. Mater. 12, 2676 (2000).
Y. Fang, W. S. Loc, W. Lu, and J. Fang, Langmuir 27, 14091 (2011).
N. V. Bondar, M. S. Brodyn, Yu. V. Yermolayeva, and A. V. Tolmachev, Physica E 43, 1882 (2011).
W. Stober and A. Fink, J. Colloid Interface Sci. 26, 62 (1968).
T. W. Melnyk, O. Knop, and W. R. Smithn, Can. J. Chem. 55, 1745 (1977).
D. Scott and Ch. A. Tout, Mon. Not. R. Astron. Soc. 241, 109 (1989).
J. Israelachvili, Intermolecular and Surface Forces, 2nd ed. (Academic Press, London, 1992).
Powder Technology Handbook, 3nd ed., Ed. by H. Masuda, K. Higashitani, and H. Yoshida (CRC Press, Taylor Francis Group, London, New York, 2006).
N. V. Bondar, J. Luminesc. 130, 1 (2010).
A. B. Yu, C. L. Feng, R. P. Zou, and R. Y. Yang, Powder Techol. 130, 70 (2003).
C. L. Feng and A. B. Yu, J. Colloid Interface Sci. 231, 136 (2000).
R. M. German, Powder Tech. 253, 368 (2003).
D. Bouvard and F. F. Lange, Acta Metal. Mater. 39, 3083 (1991).
C.-H. Kuo and P. K. Gupta, Acta Metal. Mater. 43, 397 (1995).
D. Ben-Avraham and S. Havlin, Diffusion and Reactions in Fractals and Disordered Systems (Cambridge Univ. Press, Cambridge, UK, 2000).
L. Oger, J. P. Troadec, and D. Bideau, Powder Tech. 46, 133 (1986).
A. S. Ioselevich and A. A. Kornyshev, Phys. Rev. E 65, 021301 (2002)
A. S. Ioselevich, Extended Abstract of Doctoral Dissertation (Chernogolovka, 2005).
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © N.V. Bondar, M.S. Brodin, A.M. Brodin, N.A. Matveevskaya, 2016, published in Fizika i Tekhnika Poluprovodnikov, 2016, Vol. 50, No. 3, pp. 369–376.
Rights and permissions
About this article
Cite this article
Bondar, N.V., Brodin, M.S., Brodin, A.M. et al. Photoluminescence and Confinement of Excitons in Disordered Porous Films. Semiconductors 50, 364–371 (2016). https://doi.org/10.1134/S1063782616030039
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1063782616030039