Semiconductor Physics, Quantum Electronics & Optoelectronics. 2000. V. 3, N 4. P. 463-468.

PACS: 78.60.K

Oscillator regularity of the trap activation energies
in NaCl crystals

Department of Physics, Kyiv Taras Shevchenko University,
6, Academician Glushkov prosp., Kyiv-22, 252022, Ukraine
E-mail: expdept@expphys.ups.kiev.ua

Abstract. The energy spectra of traps in NaCl crystals were studied in detail by the method of thermoluminescence. Crystals of NaCl were undoped but treated thermally in different ways. The activation energies of traps form a single oscillator series, E_n= ћw_TL(n+1/2), ћw_TL=903 cm^_1. Contrary to the other previously studied crystals having the complicated lattices, in Raman spectra of NaCl the corresponding line ћw_Ram= ћw_TL was not found. It is assumed that the oscillator regularity is governed by the polaron nature of traps. The trap activation energy is determined by a vibration level from which a transition of a charge carrier to an excited luminescence center becomes possible and depends on a distance between these centers.

Keywords: NaCl crystal, thermoluminescence, activation energy, polaron.

Paper received 21.06.00; revised manuscript received 19.09.00; accepted for publication 12.12.00.