Switchable cool and cold white emission from dysprosium doped SrZnO₂

In presented work, excitation selective novel cool and cold white emission is reported from dysprosium (Dy) doped SrZnO₂nanophosphors, synthesized by combustion technique. The host lattice provided selective excitation routes for Dy³⁺levels and intrinsic defects levels via charge transfer (270 nm) and host defects absorption bands (375 nm), respectively. The emission due to Dy³⁺levels was found to be exhibiting cool white emission and that from intrinsic defects was cold white emission, as characterized from correlated color temperature. UV irradiated glow curve analysis complemented the results by exhibiting signal due to Dy assisted traps on near UV exposure (254 nm) and that of host related traps at far UV exposure (365 nm). The luminescence phenomenon is comprehended through proposed band model. The obtained results proclaimed SrZnO₂:Dy as a potential member among white emitting phosphors to be used as standard daylight sources in commercial and aesthetic lighting.