Energy transfer induced colour tunable photoluminescence performance of thermally stable Sm3+/Eu3+ co-doped Ba3MoTiO8 phosphors for white LED applications

The combustion process has been successfully used to synthesize Ba3MoTiO8:Sm3+ and Ba3MoTiO8:Sm3+/Eu3+ co-doped phosphors for white light emitting diode (w-LED) applications. For the as-prepared phosphors, X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy techniques have been used to investigate phase confirmation, morphological analysis, and PL properties. The PL emission spectra of singly Sm3+ doped and Sm3+/Eu3+ co-doped phosphors recorded under 409 nm wavelength show intense emission in reddish-orange and red regions, respectively. For Sm3+-Eu3+ co-doped phosphors, the intensity of Sm3+ peaks show a decrease with an increase in Eu3+ ion concentration, demonstrating the energy transfer from Sm3+ to Eu3+ ions. Quadrupole-quadrupole interaction is the mechanism responsible for energy transfer from Sm3+ ions to Eu3+ ions according to Dexter's hypothesis as applied to the PL spectra. This result is in consonance with the results of PL decay curves recorded under 409 nm excitation. The Commission Internationale de I' Eclairage coordinates calculated for singly Sm3+ doped and Sm3+/Eu3+ co-doped phosphors show colour tunability from reddish-orange to pure red regions. All the results obtained finally revealed the utility of the titled phosphors as tunable red emitters needed to fabricate w-LEDs.