Synthesis and characterization of highly Eu3+-doped CaY2Sb2(ZnO4)3 red phosphors with abnormal thermal quenching performance for w-LEDs application

A novel scheelite‐type LiCaGd(WO4)3:Eu3+ red phosphors with prominent thermal stability and high quantum efficiency

“…There are three types of potential cation sites that may be replaced by Eu 3+ ions. Generally speaking, the percentage difference between the radius of the doped ion (Eu 3+ ) and the possible replacement ion (Li + /Ca 2+ /Gd 3+ ) can be estimated by the following equation 16 : $$$$\begin{equation}{D_r} = \frac{{\left[ {{R_m}\left( {CN} \right) - {R_d}\left( {CN} \right)} \right]}}{{{R_m}\left( {CN} \right)}} \times 100\% ,\end{equation}$$$$where D r is the percentage of the ion radius difference, CN is the coordination number, R m is the radius of the possible substituted ion, and R d is the radius of the doped ion. Here CN = 8, the ionic radii of Li + , Ca 2+ , Gd 3+ , and Eu 3+ are .92 Å, 1.12 Å, 1.053 Å, and 1.066 Å, 17 respectively.…”

“…There are three types of potential cation sites that may be replaced by Eu 3+ ions. Generally speaking, the percentage difference between the radius of the doped ion (Eu 3+ ) and the possible replacement ion (Li + /Ca 2+ /Gd 3+ ) can be estimated by the following equation 16 :…”