A bright orange-red emitting phosphor Ba₉La₂W₄O₂₄:Eu³⁺ with double perovskite structure and abnormal thermal quenching behavior

Abstract

In this work, a series of Eu3+ doped double perovskite phosphors Ba9La2W4O24: xEu3+ (0.2 ≤ x ≤ 1.0) were synthesized by high temperature solid-state method. The phase purity and morphology...

Highly efficient rare-earth free vanadate phosphors for WLEDs

“…The optical band gap ( E g ) can be roughly calculated using eqn (1). 41 ( αhν ) n = A ( hν − E g )where hv represents the incident photon energy, α denotes the absorption coefficient, and A denotes a constant. E g represents the indirect band gap and the direct band gap, respectively, for n = 1/2 or 2.…”

“…E g represents the indirect band gap and the direct band gap, respectively, for n = 1/2 or 2. The absorption coefficient α can be calculated by the Kubelka–Munk function (2): 41 where R stands for the reflectivity. The bandgap energies of the fabricated CMV : x Ta 5+ ( x = 0 and 0.5%) phosphors were calculated and found to be 2.59 eV and 2.62 eV, respectively (inset of Fig.…”

Preparation and luminescent properties of Ba3Na0.32Nb6O12(Si2O7)2:Eu3+ red phosphors with high color purity

“…In addition, the percentage deviation of Eu 3+ ions from Ba 2+ or Na + ions should be less than 30%. The percentage of the radius difference can be estimated from the following formula: 35 where CN represents the coordination number, R m (CN) denotes the radius of the host cation and R d (CN) means the radius of the substituent ion. The values of D r between Eu 3+ and Ba 2+ and Na + can be calculated to be 35.7% and 9.8%, respectively.…”