Optical characterization of CdS nanocrystals in Al{sub 2}O{sub 3} matrices fabricated by ion-beam synthesis

Journal Article · Mon Oct 09 04:00:00 EDT 2000 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.1316777· OSTI ID:40205296

Matsuura, D; Kanemitsu, Y; Kushida, T; White, C W; Budai, J D; Meldrum, A

We have studied optical properties of CdS nanocrystals formed by sequential Cd{sup +} and S{sup +} ion implantation into Al{sub 2}O{sub 3} matrices. Two bands related to free excitons in the wurtzite CdS are clearly observed in the absorption spectrum at low temperatures. Efficient photoluminescence (PL) appears near the absorption edge. At high temperatures, the band edge PL band consists of two components. One is the free-exciton emission with a short lifetime (several hundreds of picoseconds), while the other is the bound exciton emission at shallow localized states with a long lifetime (several nanoseconds). The temperature dependence of the band gap energy has been determined for wurtzite CdS nanocrystals. Spectroscopic analysis shows that high-quality compound semiconductor nanocrystals are fabricated by the ion-beam synthesis technique.

• Sponsoring Organization: (US)
• OSTI ID: 40205296
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 15 Vol. 77; ISSN 0003-6951
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION
EXCITONS
ION IMPLANTATION
LIFETIME
MATRICES
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
PHYSICS
SYNTHESIS
TEMPERATURE DEPENDENCE