Design, Synthesis And Property Of Polymer Phosphors In White Light Emitting Diode(WLED)

White light emitting diodes (WLEDs) were considered to be the next generation lighting systems because of advantages such as low power consumption, long lifetime and environmental protection compared to conventional light bulbs. At present, the most significant scheme was phosphor-converted white LED(pc-WLED) by combing LED chip with the down-converting phosphors. The main ways of synthesis the white LED was that ultraviolet semiconductor LED chips stimulated red, green and blue three phosphors. In this paper, the Eu(Ⅲ), Tb(Ⅲ) and Be(Ⅱ) three reactive complexes were synthesized. The three reactive complexes were emitted red, green and blue light by365nm ultraviolet, respectively. The polymer phosphors were synthesized by the copolymerization of three complexes. The polymer phosphors were emitted white light by365nm ultraviolet.(1) Two reactive Eu(Ⅲ) complexes, Eu(BA)2(Phen)UA and Eu(TTA)3UA, were synthesized through a reaction of EuCl3, benzoyl acetone (BA),1,10-phenanthroline (phen), α-thenoyltrifluoroacetone (TTA) and undecylenic acid(UA). The analysis of the infrared and ultraviolet spectrum showed that the ligands have coordinated with Eu(III)ion; The analysis of XRD and SEM images suggested that the Eu(TTA)3UA has good crystalline and neat morphology than Eu(BA)2(Phen)UA; The fluorescence spectrum indicated that being excited at365nm, the two complexes emitted the characteristic peaks of Eu(III) ion; Thermogravimetric analysis showed that decomposition temperatures of complexes were273℃and290℃, meeting the requirement of working temperature of white LED. In addition, the singlet and triplet energy levels of the ligands were calculated by quantum chemistry and luminous mechanism of the complexes were explored.(2) The reactive Tb(Ⅲ) complex, Tb(2-AA)3UA, was synthesized through a reaction of TbCl3,2-amnobenzoic acid(2-AA) and undecylenic acid(UA). The analysis of the infrared and ultraviolet spectrum showed that the ligands have coordinated with Tb(III)ion; The analysis of XRD and SEM suggested that the Tb(2-AA)3UA had crystallinity. But morphology was not neat; The fluorescence spectrum indicated that being excited at365nm, the complex emitted the characteristic peaks of Tb(III) ion; Thermogravimetric analysis showed that decomposition temperature of the complex was335℃， meeting the requirement of working temperature of white LED. In addition, the singlet and triplet energy levels of the ligands were calculated by quantum chemistry and luminous mechanism of the complex was explored.(3) The reactive Be(II) complex, Be(BTZ)2(MAA), was synthesized through a reaction of BeSO4,2-(2-Hydroxyphenyl)benzothiazole(BTZ), Methacrylic acid(MAA). The analysis of the infrared and ultraviolet spectrum showed that the ligands have coordinated with Be(Ⅱ) ion; The analysis of XRD and SEM suggested that the reactive Be(Ⅱ) complex had crystallinity. But morphology was not neat; The fluorescence spectrum indicated that being excited at365nm, the complex was emitted the characteristic peaks of Be(II) ion at460nm. Thermogravimetric analysis showed that decomposition temperature of complex was416℃, meeting the requirement of working temperature of white LED.(4) The different ratios of polymer phosphors, poly(MMA-Eu-Tb-Be), were syntheticed through the copolymerization of europium complex (Eu(TTA)3UA)、terbium complex Tb(2-AA)3UA and beryllium complex Be(BTZ)MMA with methyl methacrylate(MMA). The infrared and ultraviolet spectrum indicated that the absorption of polymers were mainly polymethyl methacrylate (PMMA); XRD and SEM analysis showed that the copolymers crystallization properties drop. They were amorphous polymer; Fluorescence spectrum analysis showed that being excited at365nm, polymers emitted the blue, green, red light characteristic peak; Thermogravimetric analysis showed that decomposition temperatures of polymer phosphors were283℃, meeting the requirement of working temperature of white LED.