Abstract
This paper studies charge transfer processes in CsI:Tl crystals by analyzing the bulk photo-conductivity spectra, the temperature behavior of the bulk photo-conductivity current and the shape and intensity of the activator emission pulse excited by an electron pulse beam and/or laser pulse emission at temperatures between 80 and 400 K. The Tl concentration in CsI:Tl crystals varies from 10-3-10-1 mass%. It has been determined that near-UV light induces a bulk conductivity in CsI:Tl crystals only when the Tl concentration is greater than 3×10-3 mass%. A mechanism is proposed to explain the charge transfer processes with photons whose energy is approximately half the width of the CsI band gap. Near-UV light causes charge transfer from I- to Tl+ ions, forming Tl0 centers in the 6p2P1/2 ground and 6p2P 3/2 excited states. The electron, assisted by phonons, leaves the Tl0 center from either the 6p2P1/2 or 6p 2P3/2 states and overcomes the 0.13 or 0.30 eV energy barrier, respectively, and subsequently populates the activator conduction sub-bands, which are found inside the band gap of CsI:Tl. The formation of activator sub-bands is possible only above the threshold Tl concentration, i.e., above 3×10-3 mass%.
| Original language | English |
|---|---|
| Pages (from-to) | 79-83 |
| Number of pages | 5 |
| Journal | Journal of Luminescence |
| Volume | 155 |
| DOIs | |
| Publication status | Published - 1 Jan 2014 |
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ASJC Scopus subject areas
- Biophysics
- Atomic and Molecular Physics, and Optics
- Chemistry(all)
- Biochemistry
- Condensed Matter Physics
Cite this
Charge transfer processes in CsI : Tl using near-UV light. / Yakovlev, V.; Trefilova, L.; Meleshko, A.; Alekseev, V.; Kosinov, N.
In: Journal of Luminescence, Vol. 155, 01.01.2014, p. 79-83.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Charge transfer processes in CsI
T2 - Tl using near-UV light
AU - Yakovlev, V.
AU - Trefilova, L.
AU - Meleshko, A.
AU - Alekseev, V.
AU - Kosinov, N.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - This paper studies charge transfer processes in CsI:Tl crystals by analyzing the bulk photo-conductivity spectra, the temperature behavior of the bulk photo-conductivity current and the shape and intensity of the activator emission pulse excited by an electron pulse beam and/or laser pulse emission at temperatures between 80 and 400 K. The Tl concentration in CsI:Tl crystals varies from 10-3-10-1 mass%. It has been determined that near-UV light induces a bulk conductivity in CsI:Tl crystals only when the Tl concentration is greater than 3×10-3 mass%. A mechanism is proposed to explain the charge transfer processes with photons whose energy is approximately half the width of the CsI band gap. Near-UV light causes charge transfer from I- to Tl+ ions, forming Tl0 centers in the 6p2P1/2 ground and 6p2P 3/2 excited states. The electron, assisted by phonons, leaves the Tl0 center from either the 6p2P1/2 or 6p 2P3/2 states and overcomes the 0.13 or 0.30 eV energy barrier, respectively, and subsequently populates the activator conduction sub-bands, which are found inside the band gap of CsI:Tl. The formation of activator sub-bands is possible only above the threshold Tl concentration, i.e., above 3×10-3 mass%.
AB - This paper studies charge transfer processes in CsI:Tl crystals by analyzing the bulk photo-conductivity spectra, the temperature behavior of the bulk photo-conductivity current and the shape and intensity of the activator emission pulse excited by an electron pulse beam and/or laser pulse emission at temperatures between 80 and 400 K. The Tl concentration in CsI:Tl crystals varies from 10-3-10-1 mass%. It has been determined that near-UV light induces a bulk conductivity in CsI:Tl crystals only when the Tl concentration is greater than 3×10-3 mass%. A mechanism is proposed to explain the charge transfer processes with photons whose energy is approximately half the width of the CsI band gap. Near-UV light causes charge transfer from I- to Tl+ ions, forming Tl0 centers in the 6p2P1/2 ground and 6p2P 3/2 excited states. The electron, assisted by phonons, leaves the Tl0 center from either the 6p2P1/2 or 6p 2P3/2 states and overcomes the 0.13 or 0.30 eV energy barrier, respectively, and subsequently populates the activator conduction sub-bands, which are found inside the band gap of CsI:Tl. The formation of activator sub-bands is possible only above the threshold Tl concentration, i.e., above 3×10-3 mass%.
UR - http://www.scopus.com/inward/record.url?scp=84904015547&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84904015547&partnerID=8YFLogxK
U2 - 10.1016/j.jlumin.2014.05.019
DO - 10.1016/j.jlumin.2014.05.019
M3 - Article
VL - 155
SP - 79
EP - 83
JO - Journal of Luminescence
JF - Journal of Luminescence
SN - 0022-2313
ER -