Investigation On Thermal Quenching Of Eu3+ Luminescence In Sr2ca(Mo/W) O-6, Gd3b(Mo/W)O-9 And Ca(Mo/W)O-4

This work reveals three structural factors for luminescent thermal quenching of Eu3+ in three molybdatetungstate phosphors. The charge transfer state (CTS) energy level was found to play a major role in thermal quenching. The linkage configuration between the MoOx group and Eu3+ and the distortion of the MoOx group were regulatory factors, whereas the structural rigidity of the host had little impact. Phosphors applicable to near-ultraviolet excitable white light-emitting diodes (NUV-WLEDs) should exhibit thermally stable luminescence and effective absorption in the NUV region. Eu3+-doped molybdate-tungstate phosphors with MoO66groups in the host matrix are potential candidates for NUV-WLEDs. However, they exhibit poor thermal quenching of Eu3+ luminescence. To obtain optimal properties, the roles of the CTS energy level, linkage configuration, distortion of MoOx groups, and structural rigidity were investigated in Eu3+-doped Sr2Ca(Mo/W) O6, Gd3B(Mo/W)O9, and Ca(Mo/W)O4. These phosphors possess typical 3D-connecting MoO66- groups, isolated MoO66- groups, and isolated MoO42- groups, respectively. This study offers a detailed analysis of the structural regulation of thermal quenching of Eu3+ luminescence.