The sensitized luminescence and tunable color of single-component Sr2MgSi2O7:Bi3+/Sm3+/Tb3+ phosphor via energy transfer for white-light emitting diodes

Processing and luminescence of Eu/Dy-doped Sr2MgSi2O7 glass-ceramics

“…Nevertheless, at the same time, the significant contribution of the red emission coming from the glassy phase hinders the persistence of the blue emission of the glass-ceramics. In this work, CL and PL measurements have confirmed that Eu 2+ is obtained in a nonreducing atmosphere through the presence of tetrahedral anionic groups such as those present in the crystalline phase Sr2MgSi2O7 of the studied glass-ceramics after the crystallization process of the glass [26,28]. Both Eu 3+ and Eu 2+ emissions are observed in these materials with the former arising from the crystalline phase.…”

“…Although the luminescence mechanisms are not fully understood, according to some theoretical studies, oxygen vacancies could be responsible for the persistent luminescence [25]. Sr2MgSi2O7 phosphors, prepared by high temperature solid state reaction, have been investigated for LED applications [26], due to their long persistence and high chemical stability. Their excitation spectrum is wide, ranging from the UV to the blue region.…”

Structure and luminescence properties of single-component melilite Sr2MgSi2O7:Ce/Tb/Sm for n-UV wLEDs

“…To clarify the thermal quenching phenomena, the temperature-dependent PL intensity could be described via the Arrhenius eqn (16): I T = I 0/ (1 + c exp(−Δ E / kT )),where I 0 and I T are the initial intensity and the intensity at different temperatures; c is a rate constant for the thermally activated escape; E is the activation energy between the lowest excited level of Ce 3+ and the bottom of conduct band, and k is the Boltzmann constant (8.629 × 10 −5 eV k −1 ). 34,35 In the inset of Fig. 7a, the ln[( I 0 / I ) −1 ] vs. 1/ KT plots are shown, where the slope gives the value of E (≈0.217 eV), indicating splendid thermal stability.…”

Tunable ultra-broadband full-visible-spectral emission of Bi3+-doped aluminate phosphors enabled by structure transformation and site occupancy engineering

“…The blue-shift can be explained as thermally active phonon-assisted tunneling from a lower energy sublevel in the upper level of Bi 3+ and the mechanism will be discussed later. 45–47…”