Model
Digital Document
Publisher
Florida Atlantic University
Description
A study of the temperature dependence of the photoluminescence spectra from Zn1-xMnxS (x = 0.01, 0.03, 0.05, 0.10, 0.20, 0.25, 0.30, 0.35 and 0.50) with different excitation energies (514.5, 488.0, 457.9, 405.5 and 365.9 nm) is given. A new band is reported in addition to the four usual emission bands. The unusual shift of the 2.1 eV (YEL) band energy is first observed in our experiments. Models for YEL, ORG (2.0 eV) and RED (1.7 eV) emission bands have been proposed. The quenching with concentration and temperature and the influence of excitation energy on the photoluminescence are discussed. The spin-spin exchange interaction between the nearest neighbor Mn^+2 ions (d-d electrons), and the exchange interaction between 3d electrons of Mn^+2 ions and the conduction or valence band electrons (d-s or d-p electrons) are introduced to interpret the shift of the bands. The strong electron-phonon interaction is also analyzed, and an effective phonon energy and a Huang-Rhys factor are obtained.
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