Thermally stimulated luminescence arising simultaneously from localized and delocalized recombination processes

• Published in: Journal of physics. D, Applied physics Vol. 39; no. 13; pp. 2670 - 2679
• Main Authors: Kumar, Munish, Kher, R K, Bhatt, B C, Sunta, C M
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 07.07.2006; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other luminescence and radiative recombination; Physics; Thermoluminescence; Defect states; Charge carrier trapping; Phosphors; Rate equation; Electron delocalization; Kinetics; Thermostimulated emission; Excited states; Heat treatments; Thermoluminescence
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/39/13/006

The thermally stimulated luminescence (TSL) arising simultaneously from localized and delocalized recombination processes is studied theoretically for a wide range of recombination and retrapping probabilities. The model proposed by Braunlich and Scharmann (BS), which considers the excitation of trapped electrons to (i) the conduction band, (ii) the excited state of the trap and (iii) the electrons from the excited state of the trap which are further raised to the conduction band during the heating phase of the TSL phosphor, has been used in the present study. The rate equations of the model, which are 'stiff', are solved numerically for a wide range of parameters using the linear heating profile. It has been found that the glow peak temperature Tm can exhibit dose dependence in localized transitions under strong retrapping, i.e. r 1 (r is the retrapping parameter for localized transitions), whereas for the other values of r, the glow peak temperature Tm is independent of dose.