Progress in triboluminescence of alkali halides and doped zine sulphides (I)

Luminescence induced by elastic deformation of ZnS:Mn nanoparticles

“…These results are in accordance with Eqs. (26), (27), (32) and (35). It is seen that when pressure is released, then the ML emission also takes place.…”

“…As ZnS crystals are non-centrosymmetric [30], the piezoelectrifiction caused by elastic deformation may give rise to the light emission [22,[31][32][33][34][35][36]. The other possibility for the occurrence of ML in ZnS:Mn nanocrystals may be the electrostatic interaction between charged dislocations and filled electrons traps [1,20,21,[37][38][39][40].…”

“…The crystals of ZnS:Cu and ZnS:Ag do not show elastico ML because the local piezoelectrification near Cu and Ag centres may not be sufficient for causing the detrapping of electrons from the filled electrons traps. Although, in the past many workers [22,[31][32][33][34][35][36] have reported the piezoelectric origin of ML, primarily on the basis of the similarity between the waveforms, spectra, temperature dependence and other characteristics of ML and EL, no attempt has been made regarding the field ionization of traps and impact excitation or ionizations of luminescence centres under internal piezoelectric field. Chudacek [31] has reported that the piezoelectric field produced by the deformations of ZnS crystals is less to cause ML, and he has suggested that the local piezoelectric field near the defect centres may be higher and it may produce ML.…”

Effect of capping on the mechanoluminescence of γ-irradiated ZnS:Cu nanophosphors

“…Colloidal II-VI ZnS are wide band gap semiconductors, which are known for their novel optical properties and have attracted much attention over the past few years. Mn-doped zinc sulphide [18][19][20] shows ML when they are deformed elastically. Chandra et al [21] reported the theory of the ML of ZnS:Mn nanoparticles, which is based on the piezoelectrically induced electron detrapping model and made a comparison between the theoretical and experimental results.…”

Mechanoluminescence induced by elastic deformation of coloured alkali halide crystals using pressure steps

“…Therefore, the materials exhibiting ML during their elastic deformation may be very useful and find applications in pressure sensors and other electronic devices. It has been reported that X or g-irradiated alkali halide crystals [14][15][16], Mn-doped zinc sulphide [16][17][18] and a few polymers [19,20] show ML when they are deformed elastically. Whereas the ML produced by the plastic deformation and fracture of coloured alkali halide crystals has been studied in detail [1][2][3], least attention has been paid to the ML induced by their elastic deformation.…”