Trapping and Recombination Properties Due to Trap Clustering

Nonequilibrium charge carriers' trapping and recombination processes in semiconductors and insulators are studied by means of the Monte Carlo method. The effect of trap clustering on trapping and recombination kinetics is considered. It is shown that such non homogeneous distribution of traps may significantly change some physical properties of a solid. The phenomena are analysed under various conditions. The influence of the temperature, the heating program and external electric field is studied. The calculations are performed for various trap parameters and various types of correlations between traps. Comparing isothermal and non isothermal spectra one can conclude that temperature dependent phenomena - such as thermoluminescence - are more sensitive to trap clustering than their isothermal counterparts - e.g. isothermal phosphorescence decay

Comparative analysis of the scintillation and thermoluminescent properties of Ce-doped LSO and YSO crystals and films

The work is devoted to the comparative analysis of the scintillation and thermoluminescent properties of the undoped and Ce-doped A2SiO5 (A = Lu, Y) orthosilicates, prepared in single crystal form by the Czochralski method and in the form of single crystalline film using the liquid phase epitaxy method. We have found that differences in the methods of material preparation resulted in the significant differences in the scintillation and thermoluminescent properties of undoped and Ce doped YSO and LSO crystals and films. Such differences are caused by the presence or absence of main host defects (first of all, oxygen vacancies and flux related impurities) as emission and trapping centers in YSO and LSO crystals and films

Comparative study of TSL and OSL properties of LSO and LSO:Ce single crystals and single crystalline films

This paper presents comparative analysis of thermally (TL) and optically (OSL) stimulated luminescence of a number of lutetium orthosilicates (LSO) single crystals and single crystalline films. Samples under study were prepared with two techniques: Czochralski method for single crystals and liquid phase epitaxy method for single crystalline films. This work describes in particular similarities and differences in OSL and TL response for alpha and beta particles between samples with different crystal form. The emission spectrum of LSO was found to extend from 350 nm to 500 nm, with a maximum near 430 nm. Intensity of TL and OSL of some samples to beta radiation was found to be quite high, indicating a potential of LSO for applications in dosimetry

Luminescence of F+F^+ and F centers in Al2O3−Y2O3Al_2O_3-Y_2O_3 oxide compounds

We summarize the results of investigation of spectral-kinetic characteristics of the luminescence of F+ and F-centers in Al2O3, YAlO3 (YAP) and Y3Al5O12 (YAG) crystals under excitation by synchrotron radiation in the transmittance and fundamental absorption ranges of these oxides. We show that the luminescence of F+ and F centers in the mentioned crystals can be excited via the corresponding intrinsic 1A?2A, 2B and 3P (F+) and 1S?3P, 1P (F) transitions of these centers, as well as via the radiative relaxation of excitons localized around F+ and F centers. In YAG crystal fast (2.3 ns) emission in the 400 nm band, excited at 3.33, 5.37 and 6.56 eV, arises from the F+-type centers, localized around YAl antisite defects (ADs). In Al2O3 and YAP crystals, the luminescence of excitons localized around F+ centers (LE(F+) centers) is revealed and the energies of formation of such excitons are determined as well. In YAG crystal the observation of the luminescence of LE(F+) centers is obscured due to presence of the large content (~0.2 at.%) of YAl ADs and formation of an excitons localized around YAl ADs and dimer F+-ADs centers

Comparative study of the luminescence of Al2O3:CAl_{2}O_{3}:C and Al2O3Al_{2}O_{3} crystals under synchrotron radiation excitation

The work is related to studying the luminescence of F and F+ centers and excitons localized around F-like centers in Al2O3 host based on the results of the comparative investigation of the luminescent properties of Al2O3 and Al2O3:C crystals under excitation by synchrotron radiation in the 3.7–15 eV range

Thermoluminescent properties of undoped and Ce-doped LSO and YSO single crystals and single crystalline films scintillators

In this work the comparative analysis of thermoluminescentproperties of undoped and Ce-doped single crystals(SC) and single crystalline films (SCF) of (LSO) and(YSO) orthosilicates were performed. The SC sampleswere prepared with the Czochralski method, and SCF weregrown by the liquid phase epitaxy technique. We show that suchdifferent methods of material preparation resulted in differentthermoluminescent properties of undoped and doped LSOand YSO SC and SCF caused by the presence host defects (first ofall, oxygen vacancies) as trapping centers in SC and formation of- pair centers in SCF