Nano Research

, Volume 11, Issue 1, pp 142–150 | Cite as

Hybridized electronic states between CdSe nanoparticles and conjugated organic ligands: A theoretical and ultrafast photo-excited carrier dynamics study

  • Tersilla Virgili
  • Arrigo Calzolari
  • Inma Suárez López
  • Alice Ruini
  • Alessandra Catellani
  • Barbara Vercelli
  • Francesco Tassone
Research Article


Formation of densely packed thin films of semiconductor nanocrystals is advantageous for the exploitation of their unique optoelectronic properties for real-world applications. Here we investigate the fundamental role of the structure of the bridging ligand on the optoelectronic properties of the resulting hybrid film. In particular, we considered hybrid films formed using the same CdSe nanocrystals and two organic ligands that have the same bidentate dithiocarbamate binding moiety, but differ in their bridging structures, one bridged by ethylene, the other by phenylene that exhibits conjugation. Based on the results of photo-excited carrier dynamics experiments combined with theoretical calculations on the electronic states of bridged CdSe layers, we show that only the phenylene-based ligand presents a strong hybridization of the molecular HOMO state with CdSe layers, that is a marker of formation of an effective bridge. We argue that this hybridization spread favors the hopping of photo-excited carriers between nanocrystals, which may explain the reported larger photo-currents in phenylene-based hybrid films than those observed in ethylene-based ones.


hybrid layer-by-layer film ultrafast spectroscopy CdSe nanoparticles molecular orbitals density functional theory 


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Hybridized electronic states between CdSe nanoparticles and conjugated organic ligands: A theoretical and ultrafast photo-excited carrier dynamics study


  1. [1]
    Querner, C.; Reiss, P.; Sadki, S.; Zagorska, M.; Pron, A. Size and ligand effects on the electrochemical and spectroelectrochemical responses of CdSe nanocrystals. Phys. Chem. Chem. Phys. 2005, 7, 3204–3209.CrossRefGoogle Scholar
  2. [2]
    Kalyuzhny, G.; Murray, R. W. Ligand effects on optical properties of CdSe nanocrystals. J. Phys. Chem. B2005, 109, 7012–7021.CrossRefGoogle Scholar
  3. [3]
    Nguyen Truong, N. T.; Ngoc Nguyen, T. P.; Park, C. Structural and optoelectronic properties of CdSetetrapod nanocrystals for bulk heterojunction solar cell applications. Int. J. Photoenergy 2013, 2013, Article ID 146582.Google Scholar
  4. [4]
    Zotti, G.; Vercelli, B.; Berlin, A.; Virgili, T. Multilayers of CdSenanocrystals and Bis(dithiocarbamate) linkers displaying record photoconduction. J. Phys. Chem. C 2012, 116, 25689–25693.CrossRefGoogle Scholar
  5. [5]
    Virgili, T.; Calzolari, A.; Suárez López, I.; Vercelli, B.; Zotti, G.; Catellani, A.; Ruini, A.; Tassone, F. Charge separation in the hybrid CdSenanocrystal–organic interface: Role of the ligands studied by ultrafast spectroscopy and density functional theory. J. Phys. Chem. C 2013, 117, 5969–5974.CrossRefGoogle Scholar
  6. [6]
    Virgili, T.; Suárez López, I.; Vercelli, B.; Angella, G.; Zotti, G.; Cabanillas-Gonzalez, J.; Granados, D.; Luer, L.; Wannemacher, R.; Tassone, F. Spectroscopic signature of trap states in assembled CdSenanocrystal hybrid films. J. Phys. Chem. C 2012, 116, 16259–16263.CrossRefGoogle Scholar
  7. [7]
    Hao, E. C.; Lian, T. Q. Layer-by-layer assembly of CdSe nanoparticles based on hydrogen bonding. Langmuir 2000, 16, 7879–7881.CrossRefGoogle Scholar
  8. [8]
    Constantine, C. A.; Gattás-Asfura, K. M.; Mello, S. V.; Crespo, G.; Rastogi, V.; Cheng, T. C.; DeFrank, J. J.; Leblanc, R. M. Layer-by-layer films of chitosan, organophosphorus hydrolase and thioglycolic acid-capped CdSe quantum dots for the detection of paraoxon. J. Phys. Chem. B 2003, 107, 13762–13764.CrossRefGoogle Scholar
  9. [9]
    Zotti, G.; Vercelli, B.; Berlin, A.; Chin, P. T. K.; Giovanella, U. Self-assembled structures of semiconductor nanocrystals and polymers for photovoltaics. 1. CdSenanocrystal-polymer multilayers. Optical, electrochemical, photoelectrochemical and photoconductive properties. Chem. Mater. 2009, 21, 2258–2271.Google Scholar
  10. [10]
    Zotti, G.; Vercelli, B.; Berlin, A.; Pasini, M.; Nelson, T. L.; McCullough, R. D.; Virgili, T. Self-assembled structures of semiconductor nanocrystals and polymers for photovoltaics. 2. Multilayers of CdSe nanocrystals and oligo(poly)thiophenebased molecules. Optical, electrochemical, photoelectrochemical, and photoconductive properties. Chem. Mater. 2010, 22, 1521–1532.Google Scholar
  11. [11]
    Liang, Z. Q.; Dzienis, K. L.; Xu, J.; Wang, Q. Covalent layer-by-layer assembly of conjugated polymers and CdSe nanoparticles: Multilayer structure and photovoltaic properties. Adv. Funct. Mater. 2006, 16, 542–548.CrossRefGoogle Scholar
  12. [12]
    Kim, D.; Okahara, S.; Shimura, K.; Nakayama, M. Layerby- layer assembly of colloidal CdS and ZnS-CdSquantum dots and improvement of their photoluminescence properties. J. Phys. Chem. C 2009, 113, 7015–7018.CrossRefGoogle Scholar
  13. [13]
    Vercelli, B.; Angella, G.; Virgili, T.; Suárez López, I.; Pasini, M. Photo-physical behaviour of CdSe nanocrystals/ bis(dithiocarbamate) linker multilayered hybrid systems. J. Nanosci. Nanotechnol. 2015, 15, 3540–3544.CrossRefGoogle Scholar
  14. [14]
    Cass, L. C.; Swenson, N. K.; Weiss, E. A. Electronic and vibrational structure of complexes of tetracyanoquinodimethane with cadmium chalcogenide quantum dots. J. Phys. Chem. C 2014, 118, 18263–18270.CrossRefGoogle Scholar
  15. [15]
    Giannozzi, P.; Baroni, S.; Bonini, N.; Calandra, M.; Car, R.; Cavazzoni, C.; Ceresoli, D.; Chiarotti, G. L.; Cococcioni, M.; Dabo, I. et al. QUANTUM ESPRESSO: Amodular and open-source software project for quantum simulations of materials. J. Phys.: Condens. Matter 2009, 21, 395502.Google Scholar
  16. [16]
    Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865–3868.CrossRefGoogle Scholar
  17. [17]
    Vanderbilt, D. Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. Phys. Rev. B 1990, 41, 7892–7895.CrossRefGoogle Scholar
  18. [18]
    Calzolari, A.; Ruini, A.; Catellani, A. Surface effects on catechol/semiconductor interfaces. J. Phys. Chem. C 2012, 116, 17158–17163.CrossRefGoogle Scholar
  19. [19]
    Grimme, S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction. J. Comput. Chem. 2006, 27, 1787–1799.CrossRefGoogle Scholar
  20. [20]
    Morris-Cohen, A. J.; Peterson, M. D.; Frederick, M. T.; Kamm, J. M.; Weiss, E. A. Evidence for a through-space pathway for electron transfer from quantum dots to carboxylate-functionalized viologens. J. Phys. Chem. Lett. 2012, 3, 2840–2844.CrossRefGoogle Scholar
  21. [21]
    Frederick, M. T.; Amin, V. A.; Swenson, N. K.; Ho, A. Y.; Weiss, E. A. Control of exciton confinement in quantum dot-organic complexes through energetic alignment of interfacial orbitals. Nano Lett. 2013, 13, 287–292.CrossRefGoogle Scholar
  22. [22]
    Frederick, M. T.; Weiss, E. A. Relaxation of exciton confinement in CdSequantum dots by modification with a conjugated dithiocarbamate ligand. ACS Nano 2010, 4, 3195–3200.CrossRefGoogle Scholar
  23. [23]
    Klimov, V. I. Spectral and dynamical properties of multiexcitons in semiconductor nanocrystals. Annu. Rev. Phys. Chem. 2007, 58, 635–673.CrossRefGoogle Scholar
  24. [24]
    Kriegel, I.; Scotognella, F.; Soavi, G.; Brescia, R.; Rodríguez-Fernández, J.; Feldmann, J.; Lanzani, G.; Tassone, F. Delayed electron relaxation in CdTenanorods studied by spectral analysis of the ultrafast transient absorption. Chem. Phys. 2016, 471, 39–45.CrossRefGoogle Scholar
  25. [25]
    Malko, A. V.; Mikhailovsky, A. A.; Petruska, M. A.; Hollingsworth, J. A.; Klimov, V. I. Interplay between optical gain and photoinduced absorption in CdSenanocrystals. J. Phys. Chem. B 2004, 108, 5250–5255.CrossRefGoogle Scholar
  26. [26]
    Knowles, K. E.; Frederick, M. T.; Tice, D. B.; Morris-Cohen, A. J.; Weiss, E. A. Colloidal quantum dots: Think outside the (Particle-in-a-)box. J. Phys. Chem. Lett. 2012, 3, 18–26.CrossRefGoogle Scholar
  27. [27]
    Azpiroz, J. M.; De Angelis, F. Ligand induced spectral changes in CdSequantum dots. ACS Appl. Mater. Interfaces 2015, 7, 19736–19745.CrossRefGoogle Scholar
  28. [28]
    Frederick, M. T.; Amin, V. A.; Cass, L. C.; Weiss, E. A. A molecule to detect and perturb the confinement of charge carriers in quantum dots. Nano Lett. 2011, 11, 5455–5460.CrossRefGoogle Scholar

Copyright information

© Tsinghua University Press and Springer-Verlag GmbH Germany 2018

Authors and Affiliations

  • Tersilla Virgili
    • 1
  • Arrigo Calzolari
    • 2
  • Inma Suárez López
    • 1
  • Alice Ruini
    • 2
    • 3
  • Alessandra Catellani
    • 2
  • Barbara Vercelli
    • 4
  • Francesco Tassone
    • 5
  1. 1.IFN–CNR, c\o Dipartimento di Fisica Politecnico di MilanoMilanoItaly
  2. 2.Istituto Nanoscienze CNR-NANO-S3ModenaItaly
  3. 3.Dipartimento di Scienze Fisiche, Informatiche e MatematicheUniversità di Modena e Reggio EmiliaModenaItaly
  4. 4.Istituto di Chimica della Materia Condensata e di Tecnologie per l’EnergiaICMATE-CNR SS di MilanoMilanoItaly
  5. 5.Center for Nano Science and Technology @PolimiIstituto Italiano di TecnologiaMilanoItaly

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