Wydział Chemii

Jerzy Sokolnicki

Eugeniusz Zych

2015

Journal of Luminescence

158

65-69

10.1016/j.jlumin.2014.09.033

Naukowa

Angielski

Artykuł

Europium doped silicate Sr₂Y₈(SiO₄)₆O₂:Eu was successfully obtained by the reaction of nanocrystalline SrO/Y₂O₃:Eu³⁺ and colloidal SiO₂ at 1000 °C in the reducing atmosphere (25%H₂/75%N₂). It has typical apatite crystal structure with the P63/m space group. The distributions of Eu³⁺ and Eu²⁺ between the two crystallographic sites 4f and 6h in the apatite structure were investigated by means of photoluminescence techniques. Results show that both ions are present in 4f and 6h sites at initial Eu³⁺ concentration of 0.1 mol%. With increasing concentration the occupancy of 4f sites by both ions increase faster. Due to significantly shifted luminescence of Eu²⁺ ions from both sites a tunable broad band emission in the spectral range of 450–650 nm can be produced varying the excitation energy. With the excitation in the wavelength range of 380–400 nm, the resultant yellow emission has spectral distribution beneficial for high color rendering index (CRI). These phosphors are efficiently excited in the wavelength range of 300–500 nm, which can be executed by a near UV- or blue-emitting InGaN chip. While the emission intensity is quite stable up to 100 °C, the emission quantum efficiency (QE) of 45% is still below the value of commercial phosphors.

oxyapatite, Eu2+, white light, LED, phosphor

http://dx.doi.org/10.1016/j.jlumin.2014.09.033

http://www.elsevier.com