稀土掺杂荧光玻璃的制备与性能研究

Preparation and Properties of Low Melting Temperature Phosphor Glass Thick Films for White LEDs

摘要:

采用市面上商用的低熔点玻璃粉、稀土荧光粉与丙烯酸树脂混合,通过丝印成膜、程序升温与淬火的方式制备了全无机低熔点高稳定性发光玻璃。采用DSC、XRD、SEM、激发发射光谱等分析手段对低熔点发光玻璃进行了各种性能分析：从研究中我们发现稀土荧光粉的平均粒径大约为18 μm；低熔点玻璃的玻璃化转变温度为285 ℃,添加适量稀土荧光粉后玻璃化转变温度升高到305 ℃左右；荧光玻璃膜中有少量孔洞,可以添加适量消泡剂或者延长保温时间来改善；荧光玻璃的晶相为玻璃相,烧结后出现了稀土荧光粉的特征峰。将0.6 mm厚的荧光玻璃经过激光切割(大小为2 mm*2 mm)与叠加蓝光发光芯片形成发光模组后测得荧光玻璃光效为115.5 lm/W,发光效率为76.2 %。因此,本课题的研究为高光效和高可靠性的小尺寸大电流大功率LED制备提供了有价值的途径。

Abstract:

Using commercial low melting temperature glass (LMTG) powders, Ce doped Y₃Al₅O₁₂ (Ce: YAG) and acrylic resin as raw materials, LMTG with Ce: YAG phosphor films for high-power white LEDs have been successfully prepared through silk-screen printing and low-temperature melt-quenching method. The LMTG with Ce: YAG phosphor thick films were studied by Differential Scanning Calorimeter, X-ray Diffraction, Photoluminescence Spectrum, and so on．The results showed that the crystal structure of Ce: YAG phosphor was formed after sintering, the glass phase was still the major phase in low melting temperature phosphor glass (LMTPG) thick films; The glass transition temperature of LMTPG films are around 305 ℃, and their glass melting temperature are around 450 ℃, both of them were significantly lower than ordinary glass. The emission peaks are a broad emission band that the center is located at 553 nm under the wavelength of 441 nm blue light excitation. the chromaticity coordinate was calculated to be (0.3794, 0.4296),the LE is 115.5 lm/W and the IE is 76.2 %. The research results indicated that the LMTPG films can be a novel promising material without any organic principle for high- power white LEDs．