Nano Archive

Photoinduced Film Formation of Colloidal CdSe Quantum Dots

Wada, Kosuke and Inasawa, Susumu and Komoto, Atsushi and Uematsu, Takafumi and Yamaguchi, Yukio (2008) Photoinduced Film Formation of Colloidal CdSe Quantum Dots. JOURNAL OF PHYSICAL CHEMISTRY C, 112 (44). pp. 17109-17114.

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Official URL: http://pubs.acs.org/doi/abs/10.1021/jp805397b

Abstract

Tri-n-octylphosphine oxide (TOPO)-capped colloidal cadmium selenide (CdSe) quantum dots (QDs) in octane formed a QD film under laser irradiation. The film was formed at a constant rate of deposition after an incubation period. The deposition rate increased linearly with increasing laser intensity and QD concentration. Addition of TOPO molecules into the suspension significantly retarded film formation. The TOPO molecules are thought to desorb from the QD surface under laser irradiation because well-capped QDs with TOPO molecules did not form a film. We propose that absorbed photons induce desorption of TOPO molecules from QDs and destabilized QDs are formed in the suspension. The formed unstable QDs attach to the substrate, resulting in the formation of a QD film. A model is proposed to analyze the kinetics of film formation. It consists of three steps: the diffusion of QDs from the bulk suspension, the photoinduced desorption reaction of TOPO molecules, and the mass transport of unstable QDs onto the substrate. Our model describes the experimental results well, and the photoreaction yield to form an unstable QD was on the order of 10(-5).

Item Type:Article
Subjects:Material Science > Functional and hybrid materials
Material Science > Nanofabrication processes and tools
ID Code:1901
Deposited By:Farnush Anwar
Deposited On:16 Dec 2008 13:44
Last Modified:13 Jan 2009 09:25

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