Red-emitting LaOF:Eu3+ phosphor modified by tetraethyl orthosilicate to boost the Luminescence intensity for LEDs

Abstract A series of red-emitting LaOF:xEu3+ (x = 0.03, 0.05, 0.07, 0.11, 0.13, 0.15 and 0.17) phosphors were successfully fabricated via precipitation reaction and calcination. The samples were evaluated by X-ray powder diffraction (XRD), transmission electron microscope (TEM), photoluminescence excitation (PLE) and emission (PL) spectra. It is found that the samples can be excited by near-ultraviolet (NUV) and blue light contributing to apply in phosphor-converted white light emitting diodes (WLEDs). The intense PL peaks were centered at 614 nm due to the 5D0 → 7F2 transition. Moreover, the PL intensity of sample modified with tetraethyl orthosilicate (TEOS) has been enhanced than that of La0.89OF:0.11Eu3+. Finally, the International Commission on Illumination (CIE) chromaticity of phosphors are located in red region. The correlated color temperature (CCT =2530 K) for La0.89OF:0.11Eu3+ modified with the concentration of 7 mol% of TEOS is in the range of “warm appearance”. The results showed that the phosphors are considered as the potential luminescence materials for warm light emitting diodes.