Ultrafast Excitation Energy Transfer in Vinylpyridine Terminated Silicon Quantum Dots

Autor:	Anja Sommer, Carola Kryschi, Hans Kupka, Michael Kunz, Christian Oelsner, Carla Cimpean
Rok vydání:	2011
Předmět:	education.field_of_study Photoluminescence Chemistry Exciton Population Relaxation (NMR) Surfaces Coatings and Films Electronic Optical and Magnetic Materials General Energy Excited state Spontaneous emission Physical and Theoretical Chemistry Atomic physics education Spectroscopy Excitation
Zdroj:	The Journal of Physical Chemistry C. 115:22781-22788
ISSN:	1932-7455 1932-7447
DOI:	10.1021/jp206495j
Popis:	Water-soluble 2- and 4-vinylpyridine terminated silicon quantum dots (SiQDs) with sizes between 2 and 3 nm were obtained by HF etching of oxidized SiQDs and subsequently passivating with vinylpyridine ligands via thermal hydrosilylation. The functionalized SiQDs emit photoluminescence in the blue-green spectrum with quantum yields around 30%. The photoluminescence is ascribed to radiative recombination of excitons confined to the SiQD core. Indication of efficient electronic interactions between excited ligand states and SiQD conduction band states has been achieved by real-time monitoring excitation relaxation dynamics on the subpicosecond time scale using time-resolved laser spectroscopy techniques. The observed ultrafast excitation relaxation dynamics involving decay and rise dynamics faster than 1 ps were ascribed to electronic excitation energy transfer from an initially photoexcited ligand state to SiQD conduction band states. These results were analyzed by performing a state population analysis on ...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ab888370ab2ae23998034cc18e72fd3a https://doi.org/10.1021/jp206495j Zobrazit plný text záznamu