Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Relaxed excited state structure and luminescence of thallium-doped caesium chloride and bromide.
AU - Mihokova, E.
AU - Nagirnyi, V.
AU - Nikl, M.
AU - Stolovich, A.
AU - Pazzi, G. P.
AU - Zazubovich, S.
AU - Zepelin, V.
PY - 1996/6/3
Y1 - 1996/6/3
N2 - Four bands, all belonging to the main thallium centres, have been detected in the emission spectra of CsCl:Tl and CsBr:Tl crystals. Their spectral, polarization and kinetic characteristics have been studied from 0.45 up to 360 K. It has been shown that the new model proposed by us recently for the relaxed excited state (RES) structure of the luminescence centre in CsI:Tl crystals is valid for CsCl:Tl and CsBr:Tl crystals as well. Two ultraviolet emission bands excited mainly in the A absorption band of Tl+ centres are ascribed to electronic transitions from trigonal and tetragonal Jahn-Teller minima of the tripler RES of Tl+. Two visible bands excitable mainly in the higher energy absorption bands of CsCl:Tl and CsBr:Tl are connected with two different off-centre configurations of self-trapped exciton perturbed by the Tl+ ion. The parameters of the corresponding excited state minima have been calculated. The mixing of the impurity and halogen excited states has been shown to decrease markedly in the sequence of anions I- --> Br- --> Cl-.
AB - Four bands, all belonging to the main thallium centres, have been detected in the emission spectra of CsCl:Tl and CsBr:Tl crystals. Their spectral, polarization and kinetic characteristics have been studied from 0.45 up to 360 K. It has been shown that the new model proposed by us recently for the relaxed excited state (RES) structure of the luminescence centre in CsI:Tl crystals is valid for CsCl:Tl and CsBr:Tl crystals as well. Two ultraviolet emission bands excited mainly in the A absorption band of Tl+ centres are ascribed to electronic transitions from trigonal and tetragonal Jahn-Teller minima of the tripler RES of Tl+. Two visible bands excitable mainly in the higher energy absorption bands of CsCl:Tl and CsBr:Tl are connected with two different off-centre configurations of self-trapped exciton perturbed by the Tl+ ion. The parameters of the corresponding excited state minima have been calculated. The mixing of the impurity and halogen excited states has been shown to decrease markedly in the sequence of anions I- --> Br- --> Cl-.
KW - SELF-TRAPPED EXCITONS
KW - OFF-CENTER POSITION
KW - ALKALI-HALIDES
KW - CRYSTALS
KW - CSCL
KW - CSBR
KW - GA+
KW - IN+
U2 - 10.1088/0953-8984/8/23/020
DO - 10.1088/0953-8984/8/23/020
M3 - Journal article
VL - 8
SP - 4301
EP - 4314
JO - Journal of Physics: Condensed Matter
JF - Journal of Physics: Condensed Matter
SN - 0953-8984
IS - 23
ER -