Synthesis of cadmium sulfide Q particles in water-in-CO{sub 2} microemulsions

Journal Article · Tue Sep 28 00:00:00 EDT 1999 · Langmuir

DOI:https://doi.org/10.1021/la990510a· OSTI ID:20013606

Holmes, J D; Bhargava, P A; Korgel, B A; Johnston, K P

Semiconductor nanoparticles of cadmium sulfide were synthesized in ammonium perfluoropolyether (PFPE-NH{sub 4}) stabilized water-in-CO{sub 2} microemulsions. The particle size was tuned by varying the water-to-surfactant molar ratio ({omega}{sub 0}): {omega}{sub 0} ratios of 5 and 10 yielded nanocrystals with exciton energies of 3.86 and 3.09 eV, corresponding to mean particle radii of 0.9 and 1.8 nm, respectively. These exciton energies are significantly higher than the bulk band gap energy for CdS (2.45 eV) due to quantum confinement effects. Effectively, {omega}{sub 0} controls the size of the compartmentalized water droplets in which the particles grow.

• Research Organization: Univ. of Texas, Austin, TX (US)
• Sponsoring Organization: National Science Foundation (NSF); USDOE
• DOE Contract Number: FG03-96ER14664
• OSTI ID: 20013606
• Journal Information: Langmuir, Vol. 15, Issue 20; Other Information: PBD: 28 Sep 1999; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CADMIUM SULFIDES
MICROEMULSIONS
WATER
CARBON DIOXIDE
PARTICLES
SYNTHESIS