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The mechanoluminescence (ML) emission during the elastic deformation of II-VI
crystals occurs either due to the electrostatic interaction between dislocation segments and
filled electron traps or due to the piezoelectrically-induced electron detrapping. According to
electrostatic interaction model, bending of dislocation segments causes electron from the
electron traps tunnel to the conduction band. The recombination of electron-hole emit energy
which is absorbed by the Mn2+
centers and the subsequent de-excitation gives rise to the light
emission and according to piezoelectrically-induced electron detrapping the local
piezoelectric field near the detect centers reduces the trap-depth, and therefore, the detrapping
of filled electron traps takes place, and subsequently the energy released non-radiatively
during the electron-hole recombination excites the Mn2+
centers and de-excitation gives rise
to the ML. The present paper reports that piezoelectrically-induced electron detrapping model
is more suitable to explain the elastico ML of II-VI phosphors.
Keywords: mechanoluminescence, triboluminescence, II-VI crystals, charged dislocations, piezoelectricity |
full paper (pdf, 1472 Kb)