Research On Electric Field Assisted Fabrication And Performance Of LED Light-coupling Patterned Fiber Coating Structures

With the miniaturization and integration of semiconductor light-emitting diodes(LED)devices,higher technical requirements have been proposed for the optical coating regulation performance.The design and manufacture of coating structures with high-performance lightcoupling functions(including light reflection,diffusion,and conversion)have become key factors.Fiber coating has the advantages of easy control of macro and micro morphology,high porosity,and high compatibility of functional particle composites.Light-coupling function can be achieved through macro-microstructure design,which has great potential in improving the lighting performance of new LED devices.However,the regulation mechanism and controllable manufacturing method of the light-coupling fiber coating structures still face great challenges.Therefore,this study carries out research on the electric field-assisted manufacture and optical performance of LED light-coupling patterned fiber coating structures,focusing on key content such as the optical mechanism and optimization design of LED fiber coating structure,disordered / patterned fiber functional coating manufacturing and integrated packaging application,to achieve the manufacture of high-performance optical coatings and improve the luminous efficiency and color performance of LED devices.The main research contents are as follows:(1)Modeling and Optical Mechanism Study of LED Light-coupling Fiber Coating StructureA finite-difference time-domain(FDTD)model was established for the basic building unit of the fiber,and the scattering characteristics of typical single,double,and triple fiber models were studied.The influence of the structural parameters of the fiber unit on the scattering crosssection was analyzed.Furthermore,an optical model of the fiber coating structure composed of a fiber group was established.The variation law of coating scattering characteristics was explored to achieve an accurate understanding of the factors affecting the coating reflectivity.The regulation mechanism of fiber medium encapsulation parameters and fiber orientation on optical scattering characteristics is revealed.It was found that the functional particle-fiber confinement structure was conducive to enhancing the fluorescence coupling intensity.It provides key theoretical guidance for the design of functional coupling fiber structure.(2)Manufacture and performance research of LED disorder fiber coating structure by electrospinningBy using the electrospinning process to regulate the fiber micro morphology,the manufacturing process of a specific light functional disorder fiber coating structure is optimized.For the highly reflective function requirements,a fiber coating structure electrospinning-mold pressing molding process is proposed to reveal the influence of fiber morphology and coating thickness on reflection performance.For high haze and high transmittance requirements,a medium packaging fiber coating structure is designed,and a fiber packaging cutting process is developed to reveal the influence of fiber cutting morphology on scattering performance.Furthermore,a fluorescent disorder fiber coating structure with strong scattering performance is proposed to reveal the influence of disorder fiber coating structure on light output performance.(3)Manufacture and performance research of LED patterned fiber coating by electrospinningThe electrospinning complex manufacturing process of patterned fiber coating is proposed,and anisotropic fiber coatings are manufactured and their optical properties are studied.The electric field simulation model of structure template electrospinning complex process is established to analyze the effect of template structure parameters on the fiber complex pattern deposition,and the template structure parameters are further optimized to achieve the transition of fiber coating from two-dimensional to three-dimensional formation and reveal its evolution rules.Based on this technology,patterned fiber coatings with regionally dimming and strong scattering performance are manufactured,the influence of pattern structure parameters on optical properties is analyzed,and the interface regional light extraction mechanism of patterned fiber coatings is explored.(4)Application of Light-coupling Fiber Coating in LED DevicesIn response to the demand for high light extraction efficiency,color uniformity,and light conversion efficiency,the fiber coating structures with specific optical function coupling are applied to LED devices.In terms of light extraction efficiency,the reflective patterned fiber coating structure was applied to multi-chip integrated LED device and secondary optical design lighting system,and the luminous efficiency of LED devices with optimized structure was improved by 31.7%.As for color uniformity,the strong scattering transmissive pattern fiber coating structure was applied to multi-chip fluorescence conversion LED packaging devices,which not only reduced the color temperature deviation of devices from 539 K to 95 K but also achieved an increase in luminous flux.In terms of light conversion efficiency,the strong scattering fluorescent fiber coating structure was integrated into a new type of quantum dot LED device and achieved a luminous efficiency of up to 202.11 lm/W,which has increased by53.6% compared to the traditional silicone packaging structure.