Study on maximum phonons in selected glass and glass-ceramics doped with rare-earth ions. The optimal and neutral maximum phonon

Basing on our previous experimental data, together with new results, and on kinetic analysis of the simple model of Pr3+ and Er3+ doped material we present how the maximum phonon value ħωmax can change when the non-crystalline matrix under interest (glass) undergoes phase conversion to polycrystalline form (glass-ceramics). We estimate the range of such a change and calculate how this change can affect the luminescence efficiency. The increase in the luminescence efficiency due to diminished value of ħωmax is, for both dopants, at most around 30%. Moreover, the diminishing phonon energy value can sometimes spoil the luminescence efficiency. This seemed to show that the common opinion: that the smaller ħωmax value the better luminescence efficiency, does not have to be true. Therefore we have performed more detailed analysis of the influence of ħωmax on the emission efficiency. It appears that in case of Pr3+ ions there is an optimal maximum phonon energy value (∼420 cm−1) whereas in case of Er3+ ions the value of maximum phonon energy can be of no importance. •Simple models were used to simulate temperature alterations of the emission spectra of RE3+ ions in glass and glass-ceramics.•The maximum phonon energy value and its changes during phase conversion from the glass to glass-ceramics has been determined.•The luminescent state population as a function of the maximum phonon energy value has been calculated for Pr3+ and Er3+ ions.•For Pr3+ ions there is an optimal phonon energy value, whereas for Er3+ ions the phonon energy value can be of no importance.