Photochemistry of colloidal semiconductors. 20. surface modification and stability of strong luminescing CdS particles

Journal Article · Wed Sep 16 00:00:00 EDT 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00253a015· OSTI ID:6012326

Spanhel, L; Haase, M; Weller, H; Henglein, A

The preparation of CdS sols with a mean diameter between 40 and 60 A and a relatively narrow size distribution is described. The colloids could be separated as solids, which in turn could be redissolved to give solutions of some 10/sup -2/ M. Activation of the particles by a cadmium hydroxide precipitate yielded fluorescing samples with a quantum yield exceeding 50%. The blue or green fluorescence occurred close to the band gap energy, which depended on the size of the particles. Violet fluorescing samples of activated ZnS-CdS co-colloids were also prepared. Photoanodic corrosion measurements showed that the activated CdS colloid was 2000 times more stable than the nonactivated one. Under laser illumination the particles became a little larger which is ascribed to an acceleration of Ostwald ripening due to local heating. Extremely intense laser light decomposed the particles into Cd + S.

• Research Organization: Hahn-Meitner-Institute Berlin, West Germany
• OSTI ID: 6012326
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 109:19; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CADMIUM COMPOUNDS
CADMIUM SULFIDES
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHEMISTRY
COLLOIDS
DATA
DISPERSIONS
EFFICIENCY
EXPERIMENTAL DATA
FLUORESCENCE
INFORMATION
INORGANIC PHOSPHORS
LASERS
LUMINESCENCE
MATERIALS
NUMERICAL DATA
PARTICLE SIZE
PARTICLES
PHOSPHORS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
QUANTUM EFFICIENCY
SEMICONDUCTOR MATERIALS
SIZE
SULFIDES
SULFUR COMPOUNDS
SYNTHESIS
ZINC COMPOUNDS
ZINC SULFIDES