Strain in colloidal heteronanocrystals with non-centrosymmetric lattices presents a unique opportunity for controlling optoelectronic properties and adds a new degree of freedom to existing wavefunction engineering and doping paradigms. We synthesized wurtzite CdSe nanorods embedded in a thick CdS shell, hereby exploiting the large lattice mismatch between the two domains to generate a compressive strain of the CdSe core and a strong piezoelectric potential along its c-axis. Efficient charge separation results in an indirect ground-state transition with a lifetime of several microseconds, almost one order of magnitude longer than any other CdSe/CdS nanocrystal. Higher excited states recombine radiatively in the nanosecond time range, due to increasingly overlapping excited-state orbitals. k? p calculations confirm the importance of the anisotropic shape and crystal structure in the buildup of the piezoelectric potential. Strain engineering thus presents an efficient approach to highly tunable single- and multiexciton interactions, driven by a dedicated core/shell nanocrystal design.

Christodoulou, S., Rajadell, F., Casu, A., Vaccaro, G., Grim, J., Genovese, A., et al. (2015). Band structure engineering via piezoelectric fields in strained anisotropic CdSe/CdS nanocrystals. NATURE COMMUNICATIONS, 6 [10.1038/ncomms8905].

Band structure engineering via piezoelectric fields in strained anisotropic CdSe/CdS nanocrystals

VACCARO, GIANFRANCO;MEINARDI, FRANCESCO;BROVELLI, SERGIO
Penultimo
;
2015

Abstract

Strain in colloidal heteronanocrystals with non-centrosymmetric lattices presents a unique opportunity for controlling optoelectronic properties and adds a new degree of freedom to existing wavefunction engineering and doping paradigms. We synthesized wurtzite CdSe nanorods embedded in a thick CdS shell, hereby exploiting the large lattice mismatch between the two domains to generate a compressive strain of the CdSe core and a strong piezoelectric potential along its c-axis. Efficient charge separation results in an indirect ground-state transition with a lifetime of several microseconds, almost one order of magnitude longer than any other CdSe/CdS nanocrystal. Higher excited states recombine radiatively in the nanosecond time range, due to increasingly overlapping excited-state orbitals. k? p calculations confirm the importance of the anisotropic shape and crystal structure in the buildup of the piezoelectric potential. Strain engineering thus presents an efficient approach to highly tunable single- and multiexciton interactions, driven by a dedicated core/shell nanocrystal design.
Articolo in rivista - Articolo scientifico
Biochemistry, Genetics and Molecular Biology (all); Chemistry (all); Physics and Astronomy (all)
English
2015
6
7905
open
Christodoulou, S., Rajadell, F., Casu, A., Vaccaro, G., Grim, J., Genovese, A., et al. (2015). Band structure engineering via piezoelectric fields in strained anisotropic CdSe/CdS nanocrystals. NATURE COMMUNICATIONS, 6 [10.1038/ncomms8905].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/88334
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