Sequential cation exchange in nanocrystals : preservation of crystal phase and formation of metastable phases
Articolo
Data di Pubblicazione:
2011
Citazione:
Sequential cation exchange in nanocrystals : preservation of crystal phase and formation of metastable phases / H. Li, M. Zanella, A. Genovese, M. Povia, A. Falqui, C. Giannini, L. Manna. - In: NANO LETTERS. - ISSN 1530-6984. - 11:11(2011 Nov), pp. 4964-4970. [10.1021/nl202927a]
Abstract:
We demonstrate that it is possible to convert CdSe nanocrystals of a given size, shape (either spherical or rod shaped), and crystal structure (either hexagonal wurtzite, i.e., hexagonal close packed (hcp), or cubic sphalerite, i.e., face-centered cubic (fcc)), into ZnSe nanocrystals that preserve all these characteristics of the starting particles (i.e., size, shape, and crystal structure), via a sequence of two cation exchange reactions, namely, Cd 2+ →Cu+ →Zn2+. When starting from hexagonal wurtzite CdSe nanocrystals, the exchange of Cd2+ with Cu+ yields Cu2Se nanocrystals in a metastable hexagonal phase, of which we could follow the transformation to the more stable fcc phase for a single nanorod, under the electron microscope. Remarkably, these metastable hcp Cu2Se nanocrystals can be converted in solution into ZnSe nanocrystals, which yields ZnSe nanocrystals in a pure hcp phase.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Cation exchange; nanocrystals; copper selenide; ZnSe; metastable phases; semiconductors
Elenco autori:
H. Li, M. Zanella, A. Genovese, M. Povia, A. Falqui, C. Giannini, L. Manna
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