Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Tuning the optical and electronic properties of colloidal nanocrystals by lattice strain

Abstract

Strain can have a large influence on the properties of materials at the nanoscale. The effect of lattice strain on semiconductor devices has been widely studied, but its influence on colloidal semiconductor nanocrystals is still poorly understood. Here we show that the epitaxial deposition of a compressive shell (ZnS, ZnSe, ZnTe, CdS or CdSe) onto a soft nanocrystalline core (CdTe) to form a lattice-mismatched quantum dot can dramatically change the conduction and valence band energies of both the core and the shell. In particular, standard type-I quantum-dot behaviour is replaced by type-II behaviour, which is characterized by spatial separation of electrons and holes, extended excited-state lifetimes and giant spectral shifts. Moreover, the strain induced by the lattice mismatch can be used to tune the light emission—which displays narrow linewidths and high quantum yields—across the visible and near-infrared part of the spectrum (500–1,050 nm). Lattice-mismatched core–shell quantum dots are expected to have applications in solar energy conversion, multicolour biomedical imaging and super-resolution optical microscopy.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Schematic of band energy changes in quantum dots induced by lattice strain.
Figure 2: Optical properties of strain-tuned QDs.
Figure 3: Comparison of emission wavelengths and quantum yields for different (core)shell and multilayered structures.
Figure 4: Powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) data of strain-tuneable QDs.
Figure 5: Continuum elasticity simulation data for high-strain (CdTe)ZnSe QDs.

References

  1. Robinson, R. D. et al. Spontaneous superlattice formation in nanorods through partial cation exchange. Science 317, 355–358 (2007).

    Article  CAS  Google Scholar 

  2. Lee, J. et al. Bandgap modulation of carbon nanotubes by encapsulated metallofullerenes. Nature 415, 1005–1008 (2002).

    Article  CAS  Google Scholar 

  3. Suhr, J. et al. Fatigue resistance of aligned carbon nanotube arrays under cyclic compression. Nature Nanotechnol. 2, 417–421 (2007).

    Article  CAS  Google Scholar 

  4. Hall, A. R., Falvo, M. R., Superfine, R. & Washburn, S. Electromechanical response of single-walled carbon nanotubes to torsional strain in a self-contained device. Nature Nanotechnol. 2, 413–416 (2007).

    Article  CAS  Google Scholar 

  5. Roberts, M. M. et al. Elastically relaxed free-standing strained-silicon nanomembranes. Nature Mater. 5, 388–393 (2006).

    Article  CAS  Google Scholar 

  6. Dabbousi, B. O. et al. (CdSe)ZnS core–shell quantum dots: Synthesis and characterization of a size series of highly luminescent nanocrystallites. J. Phys. Chem. B 101, 9463–9475 (1997).

    Article  CAS  Google Scholar 

  7. Manna, L., Scher, E. C., Li, L. S. & Alivisatos, A. P. Epitaxial growth and photochemical annealing of graded CdS/ZnS shells on colloidal CdSe nanorods. J. Am. Chem. Soc. 124, 7136–7145 (2002).

    Article  CAS  Google Scholar 

  8. McBride, J., Treadway, J., Feldman, L. C., Pennycook, S. J. & Rosenthal, S. J. Structural basis for near unity quantum yield core/shell nanostructures. Nano Lett. 6, 1496–1501 (2006).

    Article  CAS  Google Scholar 

  9. Chen, X. B., Lou, Y. B., Samia, A. C. & Burda, C. Coherency strain effects on the optical response of core/shell heteronanostructures. Nano Lett. 3, 799–803 (2003).

    Article  CAS  Google Scholar 

  10. Maki, H., Testuya, S. & Ishibashi, K. Direct observation of the deformation and the band gap change from an individual single-walled carbon nanotube under uniaxial strrain. Nano Lett. 7, 890–895 (2007).

    Article  CAS  Google Scholar 

  11. Li, Y. H., Gong, X. G. & Wei, S. H. Ab initio all-electron calculation of absolute volume deformation potentials of IV–IV, III–V and II–VI semiconductors: the chemical trends. Phys. Rev. B 73, 245206 (2006).

    Article  Google Scholar 

  12. Li, J. B. & Wang, L. W. Deformation potentials of CdSe quantum dots. Appl. Phys. Lett. 85, 2929–2931 (2004).

    Article  CAS  Google Scholar 

  13. Brunner, K. Si/Ge nanostructures. Rep. Prog. Phys. 65, 27–72 (2002).

    Article  CAS  Google Scholar 

  14. Lamberti, C. The use of synchrotron radiation techniques in the characterization of strained semiconductor heterostructures and thin films. Surf. Sci. Rep. 53, 1–197 (2004).

    Article  CAS  Google Scholar 

  15. Mueller, A. H. et al. Multicolor light-emitting diodes based on semiconductor nanocrystals encapsulated in GaN charge injection layers. Nano Lett. 5, 1039–1044 (2005).

    Article  CAS  Google Scholar 

  16. Tan, Z. N. et al. Bright and color-saturated emission from blue light-emitting diodes based on solution-processed colloidal nanocrystal quantum dots. Nano Lett. 7, 3803–3807 (2007).

    Article  CAS  Google Scholar 

  17. Hell, S. W. Far-field optical nanoscopy. Nature Biotechnol. 316, 1153–1158 (2003).

    Google Scholar 

  18. Persson, J., Hakanson, U., Johansson, M. K. J., Samuelson, L. & Pistol, M. E. Strain effects on individual quantum dots: Dependence of cap layer thickness. Phys. Rev. B 72, 085302 (2005).

    Article  Google Scholar 

  19. Wei, S. H. & Zunger, A. Predicted band-gap pressure coefficients of all diamond and zinc-blende semiconductors: Chemical trends. Phys. Rev. B 60, 5404–5411 (1999).

    Article  CAS  Google Scholar 

  20. Peng, X. G., Schlamp, M. C., Kadavanich, A. V. & Alivisatos, A. P. Epitaxial growth of highly luminescent CdSe/CdS core/shell nanocrystals with photostability and electronic accessibility. J. Am. Chem. Soc. 119, 7019–7029 (1997).

    Article  CAS  Google Scholar 

  21. Kim, S., Fisher, B., Eisler, H. J. & Bawendi, M. Type-II quantum dots: CdTe/CdSe(core/shell) and CdSe/ZnTe(core/shell) heterostructures. J. Am. Chem. Soc. 125, 11466–11467 (2003).

    Article  CAS  Google Scholar 

  22. Piryatinski, A., Ivanov, S. A., Tretiak, S. & Klimov, V. I. Effect of quantum and dielectric confinement on the exciton–exciton interaction energy in type II core/shell semiconductor nanocrystals. Nano Lett. 7, 108–115 (2007).

    Article  CAS  Google Scholar 

  23. Xie, R., Zhong, X. & Basche, T. Synthesis, characterization and spectroscopy of type-II core/shell semiconductor nanocrystals with ZnTe cores. Adv. Mater. 17, 2741–2745 (2005).

    Article  CAS  Google Scholar 

  24. Chen, C. Y. et al. Spectroscopy and femtosecond dynamics of type-II CdSe/ZnTe core–shell semiconductor synthesized via the CdO precursor. J. Phys. Chem. B 108, 10687–10691 (2004).

    Article  CAS  Google Scholar 

  25. Jeong, S. et al. Effect of the thiol–thiolate equilibrium on the photophysical properties of aqueous CdSe/ZnS nanocrystal quantum dots. J. Am. Chem. Soc. 127, 10126–10127 (2005).

    Article  CAS  Google Scholar 

  26. Adachi, S. Properties of Group-IV, III–V and II–VI Semiconductors (John Wiley & Sons, 2005).

    Book  Google Scholar 

  27. Bawendi, M. G., Kortan, A. R., Steigerwald, M. L. & Brus, L. E. X-ray structural characterization of larger CdSe semiconductor clusters. J. Chem. Phys. 91, 7282–7290 (1989).

    Article  CAS  Google Scholar 

  28. 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  CAS  Google Scholar 

  29. Yeh, C. Y., Lu, Z. W., Froyen, S. & Zunger, A. Zinc-blende–wurtzite polytypism in semiconductors. Phys. Rev. B 46, 10086–10097 (1992).

    Article  CAS  Google Scholar 

  30. Wei, S. H. & Zhang, S. B. Structure stability and carrier localization in CdX (X = S, Se, Te) semiconductors. Phys. Rev. B 62, 6944–6947 (2000).

    Article  CAS  Google Scholar 

  31. Talapin, D. V. et al. Highly emissive colloidal CdSe/CdS heterostructures of mixed dimensionality. Nano Lett. 3, 1677–1681 (2003).

    Article  CAS  Google Scholar 

  32. Manna, L., Wang, L. W., Cingolani, R. & Alivisatos, A. P. First-principles modeling of unpassivated and surfactant-passivated bulk facets of wurtzite CdSe: A model system for studying the anisotropic growth of CdSe nanocrystals. J. Phys. Chem. B 109, 6183–6192 (2005).

    Article  CAS  Google Scholar 

  33. Goldstein, A. N., Echer, C. M. & Alivisatos, A. P. Melting in semiconductor nanocrystals. Science 256, 1425–1427 (1992).

    Article  CAS  Google Scholar 

  34. Zhang, J. Z., Zhao, Y. S. & Palosz, B. Comparative studies of compressibility between nanocrystalline and bulk nickel. Appl. Phys. Lett. 90, 043112 (2007).

    Article  Google Scholar 

  35. Tolbert, S. H. & Alivisatos, A. P. High-pressure structural transformations in semiconductor nanocrystals. Annu. Rev. Phys. Chem. 46, 595–625 (1995).

    Article  CAS  Google Scholar 

  36. Zhang, X. Y., Sharma, P. & Johnson, H. T. Quantum confinement induced strain in quantum dots. Phys. Rev. B 75, 155319 (2007).

    Article  Google Scholar 

  37. Meulenberg, R. W., Jennings, T. & Strouse, G. F. Compressive and tensile stress in colloidal CdSe semiconductor quantum dots. Phys. Rev. B 70, 235311 (2004).

    Article  Google Scholar 

  38. Oron, D., Kazes, M. & Banin, U. Multiexcitons in type-II colloidal semiconductor quantum dots. Phys. Rev. B 75, 035330 (2007).

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  40. Smith, A. M., Duan, H., Mohs, A. M. & Nie, S. M. Bioconjugated quantum dots for in vivo molecular and cellular imaging. Adv. Drug Deliv. Rev. 60, 1226–1240 (2008).

    Article  CAS  Google Scholar 

  41. Yu, W. W., Wang, Y. A. & Peng, X. G. Formation and stability of size-, shape- and structure-controlled CdTe nanocrystals: Ligand effects on monomers and nanocrystals. Chem. Mater. 15, 4300–4308 (2003).

    Article  CAS  Google Scholar 

  42. Li, J. J. et al. Large-scale synthesis of nearly monodisperse CdSe/CdS core/shell nanocrystals using air-stable reagents via successive ion layer adsorption and reaction. J. Am. Chem. Soc. 125, 12567–12575 (2003).

    Article  CAS  Google Scholar 

  43. Jasieniak, J. J. & Mulvaney, P. From Cd-rich to Se-rich—the manipulation of CdSe nanocrystal surface stoichiometry. J. Am. Chem. Soc. 129, 2841–2848 (2007).

    Article  CAS  Google Scholar 

  44. Proffen, Th. & Neder, R. B. DISCUS: a program for diffuse scattering and defect-structure simulation. J. Appl. Cryst. 30, 171–175 (1997).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

The authors would like to thank Hong Yi, Zhong L. Wang, Yong Ding and A. Kumbhar for assistance with transmission electron microscopy, K. Hardcastle for help with powder X-ray diffraction, and R. Dickson, T. Lian, A. Issac and P. Nicovich for help in fluorescence lifetime data measurements. This work was supported by the NIH Roadmap Initiative in Nanomedicine through a Nanomedicine Development Centre award (PN2EY018244), and was also supported in part by NIH grants (P20 GM072069, R01 CA108468, U01HL080711 and U54CA119338), and by the DOE Genomes to Life (GTL) Program. A.M.S. acknowledges the Whitaker Foundation for generous fellowship support and S.M.N is a Distinguished Scholar of the Georgia Cancer Coalition (GCC).

Author information

Authors and Affiliations

Authors

Contributions

A.M.S. and S.M.N. conceived and designed the experiments. A.M.S. performed the experiments. A.M.S. and S.M.N. analysed the data. A.M.M. contributed materials/analysis tools. A.M.S. and S.M.N. co-wrote the paper.

Corresponding author

Correspondence to Shuming Nie.

Supplementary information

Supplementary Information

Supplementary Information (PDF 2404 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Smith, A., Mohs, A. & Nie, S. Tuning the optical and electronic properties of colloidal nanocrystals by lattice strain. Nature Nanotech 4, 56–63 (2009). https://doi.org/10.1038/nnano.2008.360

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2008.360

This article is cited by

Search

Quick links

Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research