Understanding the parameters affecting the photoluminescence of silicon nanoparticles

Silicon nanoparticles of 1-5 nm size (SiNPs) were synthesized by a bottom-up (BU) approach involving a chemical wet method. The contribution of different emitters to the overall excitation-emission matrix was analyzed on the assumption that pure substances existing in a unique form show an excitatio...

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Detalhes bibliográficos
Autores: Llansola Portolés, Manuel Jose, Pis Diez, Reinaldo, Dell'arciprete, Maria Laura, Caregnato, Paula, Romero, Juan José, Mártire, Daniel O., Azzaroni, Omar, Ceolin, Marcelo Raul, Gonzalez, Monica Cristina
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/84414
Acesso em linha:http://hdl.handle.net/11336/84414
Access Level:acceso abierto
Palavra-chave:Silicon nanoparticles
Photoluminescence
https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
Descrição
Resumo:Silicon nanoparticles of 1-5 nm size (SiNPs) were synthesized by a bottom-up (BU) approach involving a chemical wet method. The contribution of different emitters to the overall excitation-emission matrix was analyzed on the assumption that pure substances existing in a unique form show an excitation wavelength-invariant emission spectrum. The occurrence of emitters differing in size and aggregation was supported by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), time-resolved single photon counting, and time-resolved anisotropy experiments. The effect on photoluminescence (PL) of the particle surface oxidation as a result of aging is studied and compared to that of surface oxidized particles obtained by a top-down (TD) approach following an electrochemical method with HF etching. Surface oxidation to SiO x seems to introduce two different effects on the SiNP PL. An emission originated in surface states associated to SiO x was identified and observed for SiNPs synthesized by both BU and TD approaches. Blue-shifted excitation-emission spectra associated to a silicon core in embedded SiO x nanostructures were also identified. Theoretical studies were carried out to help understand the observed results. © 2012 American Chemical Society.