Structural, thermal, and luminescence kinetics of Sr4Nb2O9 phosphor doped with Dy3+ ions for cool w-LED applications

Green emission from trivalent cerium doped LaAlO3/MgO nano-composite for photonic and latent finger printing applications

“…Estimated lifetimes ( τ ) using appropriate (9) have been indicated in Table 3.where, I is the emission intensity at time t , τ 1 and τ 2 are two exponential components of τ and I ′, A 1 and A 2 are fitting parameter constants. 4 With the perusal of calculated data, it is noteworthy that with the rise in rare earth content, measured lifetimes significantly decrease implying energy transfer amongst activator ions. The energy transfer efficiencies ( η T ) and probabilities ( P ) expressed by the (10) and (11) belowwhere, τ s and τ s 0 are the estimated lifetimes of phosphor with and without Ce 3+ ions.…”

“…1,2 Current mainstream patterns of developing w-LEDs involve either the encapsulation of blue LEDs with yellow emitting phosphor YAG:Ce 3+ or pumping trichromatic blue, green, red (BRG) phosphors with UV light. 3,4 However, the rst strategy suffers due to high CCT, low color rendering index (R a < 80), halo-effect, thermal quenching, etc. In the later category, the commercially used tricolor phosphor materials are BaMgAl 10 O 17 :Eu 2+ for blue, ZnS:(Cu + , Al + ) for green and Y 2 O 2 S:Eu 3+ for red emission.…”