|
In this paper, the white LED (White Light Emitting Diode) with alkaline earth phosphate fluorescent material as the research object, using high temperature prepared by solid red phosphors excited by near-ultraviolet die. X-ray powder diffraction (X-ray diffraction) analysis of the crystal structure of the sample, by means of excitation spectrum, emission spectrum, photometer, etc. by means of the luminescence properties of the material of the study. The main contents are as follows: (1) the use of high-temperature solid-phase synthesis BaZn2 (PO4) 2: Eu3 red light-emitting materials. Its excitation and emission spectra, the results show that: the strongest excitation peak at 397 nm, and is suitable for white LED with red phosphors excited by UV InGaN die. Emission peak at 585nm, 595nm (5D0 - 7F1); 610nm, 620nm (5D0 - 7F2); 656 nm (5D0 ~ 7F3) and 688nm and 699nm (5D0 ~ 7F4), belongs to the characteristics of Eu3 emission peak. Studied BaZn2 (PO4) 2: Eu3 with Eu3 change in the concentration of the material in the main emission peak intensity of 595nm, the emission peak intensity of the first increased with the increase of the concentration of the Eu3; when the Eu3 the concentration of 3%, the maximum peak intensity; then peak intensity with Eu3 concentration increases. Eu3 concentration of 3% remains the same, different charge compensation of BaZn2 (PO4) 2: Eu3 emission spectrum intensity. With Li, Na, K, and Cl, and the charge-compensating agent could improve BaZn2 (PO4) 2: of Eu3 material emission intensity, wherein the effect of the Cl-ions is preferably followed respectively Li, Na, K (2) high-temperature solid-phase synthesis BaZn2 (PO4) 2: Sm3 red phosphor, and study its luminescent properties. An emission spectrum of three emission peaks, peaks at 569,607 and 661nm, corresponding to Sm3 4G5 / 2 → 6H5 / 2,4 G5 / 2 → 6H7 / 2, and 4G5 / 2 → 6H9 / 2, characterized in transition emission 607nm emission strongest. Excitation spectra including peak broadband at 260-460, the phosphor can either be excited near UV LED die, they can die blue LED excitation. Therefore, BaZn2 (PO4) 2: Sm3 can be used for the red phosphor for white LED. (3) high temperature solid state synthesis CaZn2 (PO4) 2: Eu3 orange red phosphor and its luminescence properties studied. The phosphor 350nm-410nm broadband excitation peak, suitable for excitation UVLED die, stimulate the main peak at 394 nm. Under UV excitation emission peak at 585nm and 595nm, 615 nm and 622 nm, 654nm and 687 nm and 700 nm four groups linear peaks, respectively, corresponding to Eu3 (of 5D0 → 7F1) (5D0 → 7F2), (5D0 → 7F3) and characteristics of transition (5D0 → 7F4), 595nm emission peak strongest. Discussion the doped Eu3 concentration on the emission intensity of the sample, its optimum doping concentration of 10%, and Eu3 emitted orange / red ratios vary with the concentration relationship. Comparative Analysis MZn2 (PO4) 2: Eu3 (Ca, Ba) both matrices of Eu3 emission quenching concentration differences. Found that the addition of different charge compensation agent Li, Na, K, are luminous intensity can be improved, especially Li Best (4) the use of high-temperature solid-phase synthesis Sr3Y (PO4) 3: Eu3 red light-emitting materials. Its excitation and emission spectra, observation results show: the strongest excitation peak at 399 nm, and is suitable for red phosphors excited by UV (InGaN) die white LED with. Emission peak to 592nm, and 598 nm (of 5D0 → 7F1), 617nm, 622 nm was taken and 630nm (5D0 → 7F2), 657nm (5D0 → 7F3) and 690nm (5D0 → 7F4), the characteristics of Eu3 emission peak. The emission intensity changes with the concentration. With the increase of the Eu3 ions found no concentration quenching phenomenon, but the presence of quenching trend. And further study the matrix Sr3Y (PO4) 3 Bi3 on Eu3 sensitized.
|