Mn^(4+)掺杂氟化物窄带发射红色荧光粉的研究进展

Recent advances in Mn^(4+)-doped fluoride narrow-band red-emitting phosphors

白光发光二极管(light emitting diode,LED)由于其具有节能、环保、使用寿命长等优点被誉为新一代固体光源,在照明、显示等领域具有十分广阔的应用前景.目前,商业化的白光LED主要由蓝光LED芯片与黄色荧光粉Y_3Al_5O_(12):Ce^(3+)(YAG:Ce^(3+))组合而成.然而,荧光粉YAG:Ce^(3+)光谱中红光成分不足导致当前白光LED的显色指数偏低(CRI,Ra<80)、色温偏高(CCT>4000 K),难以满足室内照明以及宽色域液晶显示(LCD)背光源等应用的要求.在蓝光芯片+黄色荧光粉组合中添加适量红色荧光粉是改善白光LED光色性能的有效方法之一.近年来Mn^(4+)掺杂氟化物窄带发射的红色荧光粉因其具有发光效率高、热稳定性好、色纯度高以及可以液相合成等突出优点受到了广泛关注,且其谱峰比商用氮化物红色荧光粉更窄,在宽色域液晶显示背光源应用中有广阔的商业前景.本文概述了Mn4+掺杂氟化物窄带发射红色荧光粉的最新研究进展,特别是对其结构特性、合成工艺、发光特性及应用特性等加以剖析,指出了当前Mn^(4+)掺杂氟化物红色荧光粉所面临的挑战,并对其未来的发展及应用进行了展望.

White lighting emitting diodes（WLEDs） are considered as next generation solid-state lighting source, show great potential for lighting and displays application, because of their superior properties of energy saving, environment-friendliness and long lifetime. To date,the most popular commercial WLEDs are constructed by the combination of blue light emitting InGaN chip and yellow phosphor Y3Al5O12：Ce3＋（YAG）. However, owing to the inherent deficiency of red emission from YAG：Ce3＋, the well-established strategy suffers from a low color rendering index（CRI, Ra〈80） and high correlated color temperature（CCT〉4000 K）, which makes it inappropriate for applications in indoor lighting or backlighting in liquid-crystal display（LCD）. To solve this problem, a suitable extra red emitting phosphor should be added into the aforementioned design. Currently, narrow-band Mn4＋-activated fluorides have gained considerable attention due to their superiorities of sharp line emission, high luminescence efficiency, good thermal stability, high color purity,and solution-availability, which are highly important to the application for WLEDs. Here in this review, we overview the recent development of Mn4＋ doped fluoride red phosphors, especially focusing on the investigations on crystal structure, synthetic approaches,optical properties and promising application for WLEDs. Afterwards, the existing challenges and future developments have been proposed pointedly.