Exciton self-trapping in AgCl nanocrystals

Citation
H. Vogelsang et al., Exciton self-trapping in AgCl nanocrystals, PHYS REV B, 61(3), 2000, pp. 1847-1852
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICAL REVIEW B
ISSN journal
1098-0121 → ACNP
Volume
61
Issue
3
Year of publication
2000
Pages
1847 - 1852
Database
ISI
SICI code
1098-0121(20000115)61:3<1847:ESIAN>2.0.ZU;2-L
Abstract
Self-trapping of excitons is reported in AgCl nanocrystals embedded in a cr ystalline KCI matrix. The particles, observed by atomic force microscopy, h ave radii of several nanometers. Due to the spatial confinement only recomb ination of the self-trapped exciton (STE) is observed. STE(Br-) and donor-a cceptor pair recombination are absent. The time and temperature behavior of the emission is found to be significantly different from that in bulk AgCl . It is concluded that this is due to different self-trapped exciton config urations: The diffuse electron is spatially confined and centered in the na nocrystal whereas the compact hole, self-trapped at different lattice sites , causes variations in wave-function overlap in the different STEs. Optical ly detected magnetic resonance measurements reveal changes in g-values and a decrease by a factor of two in the magnitude of the Zero-field splitting of the triplet state. They also demonstrate that the AgCl nanocrystal latti ce axes are oriented along the axes of the KCl matrix.