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), Vol. 109:19
• Country of Publication: United States
• Language: English

Related Subjects

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