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Journal of Physical Studies 7(1), 84–92 (2003)
DOI: https://doi.org/10.30970/jps.07.84 EXOELECTRON ENERGY SPECTRUM AND ESCAPE PROBABILITY IN THE RECOMBINATIONAL MODEL OF THE EXOELECTRON EMISSIONP. V. Galiy, O. Ya. Mel'nyk
Ivan Franko National University of Lviv, Department for
Semiconductors Physics |
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Exoelectron emission model was developed within the frame of the bulk thermo-activated radiative defects recombination and band-energetic Auger-like mechanisms for the wide-band-gap caesium bromide insulating crystal case due to peculiarities of its structure. The model is based on the assumption of the exciton annihilation energy being the source of the exoemission phenomenon. Wave function for the $F$-center electron, to simplify the calculation, was chosen in the form designed by Pekar. Matrix element of electron transition from trapped ($F$-center) into free (exoelectron) state was attained. The elementary quantum-mechanical calculations were executed to obtain exoelectron energy spectra and their characteristics. The derived results correlate with the experimental ones. The exoelectron emission probability has been calculated on the basis of the assumption of the isotropic angular distribution of the excited electrons and its exponential energy distribution with the same average energy $\left\langle E\right\rangle.$ The exoelectrons effective escape depth zone under their isotropy dissipation on $LO$-phonons and defects scattering is estimated. Due to the correspondence of theoretically calculated to experimental spectra, there was made a conclusion about crucial role of the near-surface layers in the resulting exoelectron energy spectra formation.
PACS number(s): 46.25.Cc, 79.75+g, 82.56.Na