研究了Pr^3+,Sm^3+掺杂对YAG∶Ce发射光谱及其荧光寿命的影响。观察到当掺杂Pr^3+时,在609nm处出现Pr^3+的发射峰,而掺杂Sm^3+时,在616nm处呈现Sm^3+的发射峰。掺杂Pr^3+或Sm^3+增加红光区的发射峰将有利于提高YAG∶Ce荧光粉的显色性。实验中测定了(Y0.95Sm0.01Ce0.04)3Al5O12、(Y0.95Pr0.01Ce0.04)3Al5O12、(Y0.96Ce0.04)3Al5O12的荧光寿命(τ),观察到在YAG∶Ce中掺入Pr^3+或Sm^3+使Ce^3+的荧光寿命减小。实验结果表明,少量掺杂Pr^3+或Sm^3+并未引起基质的结构的变化。
Due to a lot of advantages, such as energy saving, high efficiency and long lifetime, white light emitting diode (W-LED) has been widely applied in many areas. The common way to fabricate W-LED is by painting a yellow-emitting phosphor on the blue LED chip. Since blue LED emits from 430 nm to 480 nm, the absorption energy for a better yellow-emitting phosphor should match that spectral region of LED emission. YAG: Ce^3+ shows a strong broad band absorption around 465 nm and emits at about 540 nm; therefore it has been used as the main yellow-emitting phosphor in W-LED. However, the weakness of W-LED composed of blue LED and YAG: Ce^3+ is the shortage of its red-emission component. To overcome this weakness, one of the following approaches could be chosen: 1. Adding some red-emitting components into YAG: Ce^3+ phosphor; 2. Doping other cations in YAG: Ce^3+ lattice. Lanthanide ions are the appropriate ones for this doping YAG: Ce^3+ since their ionic radii are very close to that of Y^3 + ion. Many papers have reported the study on lanthanide doping. In this paper, the doping effects of Pr^3 + and Sm^3+ on the luminescence properties and fluorescence lifetime of YAG: Ce were systematically studied in order to understand the rule. Phosphors were synthesized by high-temperature solid-state reaction under reducing atmosphere. ray diffraction patterns presented Pr^3+ and Sm^3+ can partially replace Y^3 + and the lattice phases The X-ray diffraction patterns presented Pr^3+ and Sm^3+ can partially replace Y^3 + and the lattice phases do not change . The doping effects of Pr^3 + and Sm^3+ on the luminescence properties and fluorescence lifetimes of (Y0.96%-xLnx Ce0.04)3Al5O12 (Ln = Pr^3+, Sm^3+) were studied. The emission and excitation spectra of the samples are recorded. In the (Y0.96-xPr, Ce0.04)3Al5O12 system the emission band of Pr^3 + was at about 609 nm; and in the (Y0.96-xSmx Ce0.04) 3Al5O12 system the crease the color rendering index (CRI