Preparation And White LED Application Of Aluminum/Silicon-based Nanofiber Phosphors By ElectroSpinning

Energy efficiency is always an important parameter for light and illumination sources.White light-emitting diodes(WLEDs)have attracted increased attention in the fields of ligiting due to their low energy consumption,long lifetime,mercury-free composition,good reliability and high efficiency.The main traditional two-color WLEDs are usually fabricated by combining a blue InGaN LED chip with a yellow YAG:Ce phosphor in market.However,the solid-phase method is mainly synthesis method of YAG:Ce phosphor,which has narrow emission spectrum and lacks red light,as well as,the particle size is large because of high synthesis temperature and easy to agglomerate,making the poor color render:ing index and chroma saturation of the prepared LED light Electrospinning process is simple,inexpensive,uniform as preparing nanofibers and important in many application fields.Based on this,the Electrospinning process was used to prepare LED phosphors with good morphology.In this paper,the preparation of aluminum/silicon nanofibers phosphor precursor using single-axis electrospinning technology were reviewed.The crystallinity,morphology,element composition and light-emitting characteristics of the samples were characterized by XRD,SEM,EDS and PL spectra.The detailed work of this paper is as follows:(1)The nanofiber precursors prepared by electrospinning were sintered to obtain uniformly sized fibrous phosphor.The effects of different temperature and doping concentration on the crystal form,morphology and luminescence of CaAl12O 19 phosphors were systematically studied.Compared with the phosphor prepared by solid phase method,it is easy to find that the electrospinning method can greatly reduce the synthesis temperature of the phosphor and use less energy consumption;The phosphor with uniform size can be easy obtained and the luminous intensity can be improved.The LED device was fabricated using a phosphor with Mn4+ optimum doping concentration of 0.5 at%,and showed a warm white light source with a color rendering index of 88.5 and a color temperature of 4553 K.(2)The Ba9Lu2Si6O24 nanofiber phosphor was obtained by electrospinning process.The influence of different temperature on the morphology was studied systematically,and the crystal and luminescence changes of Ce3+ ions were discussed in detail.By adding Mn2+ ions,increasing the red band in the spectrum,using the prepared Ba8.85Lu1.85Si6O24Ce0.15Mn0.15 phosphors to obtain the color rendering index of 82,color temperature 7079 K,color coordinates(0.2990,0.3280)lumen efficiency 78 lm/W white LED devices(3)The ?-Ca2SiO4 nanofiber phosphor with uniform size was prepared by the electrospinning process combined with the heat treatment process.electrospinning method Compared with solid phase method is more easily synthesized ?-Ca2SiO4 phosphor.The effect of different concentrations of Al3+ and Ce3+ ions on the crystal structure was studied.The conditions were optimized and the pure phase y-Ca2SiO4 phosphor was synthesized.The bright white LED fabricated by using a single phosphor has the color rendering index of 84,Color temperature of 4550 K,color coordinates of(0.3508,0.3390)located at the warm white area.