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Name (Title):
Saim Emin, Norihito Sogoshi, Alexandre Loukanov and Seiichiro Nakabayashi
Affiliation:
Saitama University, Faculty of Sciences, Department of Chemistry
Address:
255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570, JAPAN
Email: sei@chem.saitama-u.ac.jp, eminsaim@yahoo.com
Home Page: http://park.saitama-u.ac.jp/~nakabayashi-lab/
Presentation Title:
Synthesis and Characterization of NIR-Emitting Semiconductor Nanocrystals
Abstract:
Luminescent CdSe, CdTe and ternary CdSeTe
nanocrystals (quantum dots-QDs), showing tunable
luminescence properties from green to near infrared are
synthesized by one-step addition of Se, Te or mixture of
both ions into the Cd precursor solution at elevated
temperature of 300 ˚C. The resulting nanocrystals reveal
very narrow PL emission of about 35 nm at full width at
half maximum. By changing the stoichiometry of Se
and Te the PL emission of the ternary QDs are tuned
from red to NIR region of the wavelength. Transmission
Electron Microscope (TEM) equipped with Energy
Dispersive X-ray (EDX) module allowed us to
characterize the composition of the Qdots. The effect of
the composition on optical properties of the
nanocrystals will be presented as well. Steady state
photoluminescence spectra will be given for each composition under investigation. Typical
photoluminescence spectra for ternary CdSeTe are shown in Fig. 1. By increasing the sizes of the
QDs the spectra shifts to longer wavelength (lower energies). Fluorescence lifetimes will be
presented for the ternary QDs. Photoluminescence excitation spectra of the QDs will be
emphasized. The ternary QDs synthesized by us are reproducible and can be used in biosensing,
electroluminescent devices, quantum dot-lasers and in optoelectronic devices.
References:
[1] R. E. Baley, S. Nie, J. Am. Chem. Soc. 125 (2003) 7101.
[2] E. Jang, S. Jun, L. Pu, Chem. Comm. (2003) 2964.
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Poster Session PM-28
Fig.1. Emission spectra of ternary CdSeTe
QDs.