首次提出了一种基于静电纺丝工艺以柔性PET为基底的新型LED远程荧光片的制备方法,实现了蓝色LED芯片与荧光粉层相分离的免封装器件结构。采用静电纺丝工艺制备了黄色荧光片和红色荧光片,并研究了黄色荧光片的透射率、吸收率、PL谱及红色荧光片对白光LED的光学性能参数的影响,包括光通量、相关色温、光效。实验结果表明,所制备黄色荧光片在可见光波段具有良好的透光性,荧光片的光谱完全由荧光粉来决定,不需要考虑复杂工艺的影响;使用红色荧光片可以在保持高光效的同时将球泡灯的相关色温由5 595 K降低为3 214 K,这在曲面发光及色温调节方面为灯具设计提供了广阔的空间。

A new method of preparing the LED remote fluorescent sheet based on the electrostatic spinning process with flexible PET substrate is proposed, and the free package device structure is realized by separating the blue chip and the phosphor layer. Electrostatic spinning process is a new technology to prepare fluorescent sheet with high performance, which can effectively solve the problem of uneven distribution of fluorescent powder. The yellow and red fluorescent sheets were prepared by electrostatic spinning process. The transmittance, absorption rate, PL spectra of yellow fluorescent sheet were studied. The effect of red fluorescent sheet on the optical performance parameters of white LED, including the luminous flux, correlated color temperature and luminous efficiency, was also studied. Experimental results show that the prepared yellow fluorescent sheets have good light transmission in the visible band. Fluorescent spectrum is completely determined by the fluorescent powder, so we do not need to consider the influence of complex processes. Using red fluorescent sheet can keep high efficiency and decrease the correlated color temperature of the bulbs from 5 595 K to 3 214 K at the same time, which provides more chance for the design of lamps and lanterns in luminescence of curved surface and regulation of color temperature. With the continuous improvement of the technology, the remote fluorescent technology based on the electrostatic spinning process will be more perfect, the performance of the product will be further improved, and the pace of the white LED going into the lighting field is promoted.