Laser writing of semiconductor nanoparticles and quantum dots
- Department of Physics, University of Missouri-Rolla, Rolla, Missouri 65409 (United States)
Silica aerogels were patterned with CdS using a photolithographic technique based on local heating with infrared (IR) light. The solvent of silica hydrogels was exchanged with an aqueous solution of the precursors CdNO{sub 3} and NH{sub 4}OH, all precooled to a temperature of 5 deg. C. Half of the bathing solution was then replaced by a thiourea solution. After thiourea diffused into the hydrogels, the samples were exposed to a focused IR beam from a continuous wave, Nd-YAG laser. The precursors reacted in the spots heated by the IR beam to form CdS nanoparticles. We lithographed features with a diameter of about 40 {mu}m, which extended inside the monoliths for up to 4 mm. Samples were characterized with transmission electron microscopy and optical absorption, photoluminescence, and Raman spectroscopies. Spots illuminated by the IR beam were made up by CdS nanoparticles dispersed in a silica matrix. The CdS nanoparticles had a diameter in the 4-6 nm range in samples exposed for 4 min to the IR beam, and of up to 100 nm in samples exposed for 10 min.
- OSTI ID:
- 20634562
- Journal Information:
- Applied Physics Letters, Vol. 85, Issue 24; Other Information: DOI: 10.1063/1.1836000; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ABSORPTION
AMMONIUM HYDROXIDES
AQUEOUS SOLUTIONS
CADMIUM SULFIDES
HEATING
HYDROPHYLIC POLYMERS
NEODYMIUM LASERS
PARTICLES
PHOTOLUMINESCENCE
PRECURSOR
QUANTUM DOTS
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SEMICONDUCTOR MATERIALS
SILICA
SILICON COMPOUNDS
SOLVENTS
THIOUREA
TRANSMISSION ELECTRON MICROSCOPY