Preparation of monodispersed cadmium sulfide nanoparticles by means of size selective photocorrosion

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:370809

Matsumoto, H; Yoneyama, H ^[1]

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1. Osaka Univ. (Japan)

Several attempts have been reported for preparation of monodispersed semiconductor nanoparticles (Q-particles), but it is still a challenging problem to pursue a useful technique for the preparation of monodispersed Q-particles. In this paper, a new technique in which size-selective photocorrosion is utilized is reported. Irradiation of Q-CdS in aerated solutions containing methyl viologen results in its rapid photocorrosion. Since the absorption onset of Q-CdS colloid containing particles of various sizes is determined by the largest particle, irradiation of the colloids with monochromatic light whose wavelength is a little shorter than the absorption onset causes the photocorrosion of the largest particles to give smaller particles until they do not absorb the irradiated photons any more. By changing the monochromatic light for irradiation to shorter one step by step, the absorption onset of the resulting colloids was finally shifted from 520 nm to 450 nm, and simultaneously exciton peaks became appeared clearly in the absorption spectrum. The mechanism of photocorrosion and the evaluation of the monodispersiveness will be discussed.

• OSTI ID: 370809
• Report Number(s): CONF-960376--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ABSORPTION
CADMIUM SULFIDES
COLLOIDS
IRRADIATION
PARTICLE SIZE
PHOTONS