深红色发光材料BaZnAl₁₀O₁₇:Cr³⁺的光致发光性能研究

Synthesis and Photoluminescent Properties of Deep-Red Emission Phosphor BaZnAl₁₀O₁₇:Cr³⁺

摘要: 本文采用高温固相法成功制备了新型铝酸盐基深红色发光材料BaZnAl₁₀O₁₇:Cr³⁺，通过XRD、光谱测量以及热衰减测量等系统表征了材料的晶体结构和发光性能。光谱研究表明，在562 nm激发下，发光材料呈现强烈的深红色窄发射峰，峰值为691 nm，归属于Cr³⁺在AlO₆八面体格位的²E→⁴A₂的辐射跃迁。在691 nm监控下，材料在405和562 nm有两个强吸收峰，分别对应于Cr³⁺的⁴A₂→⁴T₁(⁴F)和⁴A₂→⁴T₂(⁴F)跃迁。在此基础上，本文结合物理模型讨论了Cr³⁺离子的荧光寿命和浓度猝灭机理。在应用方面，本文详细研究了发光材料的热稳定性能并讨论了其可能的热猝灭机理。测试结果表明，在150℃时，材料的发光强度依然保持在25℃时的53%，优于文献报道的同类pc-LEDs用发光材料SrMgAl₁₀O₁₇:Cr³⁺ (34.49%)及Ca₃Al₄ZnO₁₀:Mn⁴⁺，Mg²⁺ (51%)，由此说明深红色发光材料BaZnAl₁₀O₁₇:Cr³⁺在pc-LEDs等功能器件上具有良好的应用潜力。

Abstract: Cr³⁺-activated aluminate-phosphors BaZnAl₁₀O₁₇:Cr³⁺ with emission in deep-red region are synthesized successfully by high temperature solid-state reaction. Their crystal structure and photoluminescent properties are characterized by XRD, photoluminescence spectroscopy, temperature-dependent emission spectra, etc. The excitation spectra of BaZnAl₁₀O₁₇:Cr³⁺ phosphors monitored at 691 nm, exhibit two broad bands peaked at 405 nm and 562 nm, which are corresponding to ⁴A₂→⁴T₁(⁴F) and ⁴A₂→⁴T₂(⁴F) transitions of Cr³⁺, respectively. Under the excitation of 562 nm, those phosphors display an intense narrow deep-red emission band centered at 691 nm, which can be attributed to the ²E→⁴A₂ transition of Cr³⁺ incorporated in the AlO₆ octahedral sitesofAl³⁺. The concentration-dependence lifetime and the concentration quenching mechanism of BaZnAl₁₀O₁₇:Cr³⁺ phosphors are discussed. The thermal stability of BaZnAl₁₀O₁₇:Cr³⁺ and the possible thermal quenching mechanism are discussed as well. It can be observed that the emission intensity of phosphors obtained in this work exhibit a mild decrease to 53% at 150˚C comparing with that at 25˚C, which is literally better than similar pc-LEDs phosphors, SrMgAl₁₀O₁₇:Cr³⁺ (34.49%) and Ca₃Al₄ZnO₁₀:Mn⁴⁺, Mg²⁺ (51%) reported in the literature, indicating that our phosphors have a better thermal stability. Thus, it demonstrates that BaZnAl₁₀O₁₇:Cr³⁺ is a potential deep-red emission phosphor for pc-LEDs and other functional devices.