Title

Infra Red Quantum Dot Photolithography

Abstract

CdS quantum dots were fabricated photolithographically on the surface and in the bulk of silica hydrogels, as well as on the surface of planar substrates. Silica hydrogels were prepared with a standard base-catalyzed route, and the solvent was exchanged with a cold aqueous solution of Cd(NO3)2, NH4OH, thiourea, and a capping agent, e.g., 2-mercaptoethanol. The samples were then exposed to a focused infrared beam produced by a continuous-wave Nd:YAG laser. The precursors reacted upon heating, and CdS nanoparticles formed in the illuminated regions. Use of capping agents allowed to control the mean particle size, while focusing of the beam inside hydrogel monoliths generated nanoparticles in their bulk, but not at the surface. Planar substrates were patterned by illuminating a precursor solution spin-coated on the substrates. The average size of the CdS nanoparticles could be varied between about 1.5 and 4.5 nm by varying the type and the concentration of the capping agents.

Department(s)

Physics

Second Department

Chemistry

Keywords and Phrases

Photolithography; Quantum Dots; Semiconductor Nanoparticle

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2006 Springer Verlag, All rights reserved.

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