Premium
Thermoluminescence Study of Charge Traps in Polycrystalline Layers of Phenanthrene
Author(s) -
Dreger Z.,
Kalinowski J.,
Davoli I.,
Stizza S.,
Feliziani S.
Publication year - 1988
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221490139
Subject(s) - thermoluminescence , phenanthrene , crystallite , range (aeronautics) , excitation , atomic physics , substrate (aquarium) , materials science , charge carrier , charge (physics) , chemistry , molecular physics , analytical chemistry (journal) , crystallography , physics , optoelectronics , luminescence , oceanography , chromatography , quantum mechanics , environmental chemistry , composite material , geology
UV‐induced thermoluminescence (UVTL) experiments are carried out on polycrystalline films of phenanthrene. Applying the fractional glow technique the distribution of charge traps in energy is determined. The distribution appears to be quasi‐continuous within the energy range 0.25 to 0.60 eV, peaking at two energies E t (I) = 0.27 eV and E t (II) = 0.43 eV, and showing a cutoff at its low‐ and high‐energy edges. The peaks reflect the two maxima of the UVTL glow curves and correspond to different emission centers. It is the consequence of the distance and concomitant energy distribution of geminate trapped electron–hole pairs produced at the stage of the TL excitation. The results demonstrate that the discrete trap‐model, used extensively for the polycrystalline aromatic compounds, is not applicable to phenanthrene evaporated under vacuum onto a rigid substrate.