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Decay Kinetics of Triplet Molecular Excitons in Alkali Cyanides
Author(s) -
Henriques A. B.,
von Der Weid J. P.
Publication year - 1985
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221320237
Subject(s) - luminescence , exciton , excited state , alkali metal , chemistry , excitation , kinetics , phonon , quenching (fluorescence) , atomic physics , ion , crystal (programming language) , photochemistry , materials science , fluorescence , condensed matter physics , physics , optoelectronics , organic chemistry , quantum mechanics , computer science , programming language
The decay kinetics and emission intensity of the UV luminescence associated to the a 3 II → X i ∑ + electronic transition of the CN − molecular ion in alkali cyanide crystals are investigated between 2 and 100 K. The results indicate that the a 3 II molecular excitons are coupled to lattice phonons, becoming self‐trapped at low temperatures. The splitting of the a 3 II state in the crystal field yields a single active state in NaCN and KCN whereas at least two active states are found in RbCN and CsCN. Thermal activation of migration of the molecular excitation leads to a quenching of the luminescence. These effects can be qualitatively understood by a charge transfer component in the excitation, already suggested from earlier studies.