Preparation And Performance Of Continuous Tunable Broadband Fluorescent Glasses

Broadband phosphor-converted light-emitting diode（pc-LED）has the characteristics of high luminous efficiency,long life and low energy consumption.It is expected to replace traditional broadband light sources（incandescent lamps,xenon lamps,halogen lamps）in the field of portable spectrometer applications.However,pc-LED are mainly composed of LED chips and multicolor phosphors encapsulated by organic resins.The reabsorption effect between multicolor phosphors leads to low quantum efficiency,while the thermal stability of organic packaging materials is poor,which reduces the service life of the device.In response to the above problems,this paper uses fluorescent glasses instead of organic resin packaging materials for packaging.Compared with organic encapsulated phosphors,fluorescent glass has better thermal conductivity and thermal stability,which can completely solve the problem of pc-LED organic encapsulation materials at this stage.Therefore,the research direction of this paper is to design a continuous tunable broad-spectrum doped luminescent ions fluorescent glasses,and package it with blue LED chips to achieve broad-spectrum emission.In this paper,fluorosilicate（SF）glass doped with Mn²⁺was prepared by high temperature melting method,which obtained relatively excellent physical and optical properties.And on this basis,Ce³⁺/Mn²⁺co-doped fluorosilicate glass was prepared.Compared with single-doped Mn²⁺fluorosilicate glass,the optical and physical properties are further improved.In addition,the light source and optical fiber coupling system design of pc-LED based on fluorescent glass package is also carried out.The research content of the full text is as follows:1、Based on the excellent physical properties and good optical properties of fluorosilicate glass,a single-doped SF fluorescent glass with Mn²⁺was prepared.The results show that:its transmittance in the visible light region is 90%;The effect of different concentrations of Y₂O₃ on the optical properties of Mn²⁺single-doped SF glass was studied.The quantum efficiency was increased from27.9%to 43.8%,and the thermal stability was improved while the thermal quenching was reduced.The glass transition temperature was increased from 546℃To 665℃;In addition,by adjusting the doping concentration of Mn²⁺,a continuously adjustable broad spectrum emission from green to orange is achieved（475-800nm）.2、Although the fluorosilicate glass doped with Mn²⁺has improved the range of the broad spectrum,it still lacks the blue emission band.At the same time,due to the spin forbidden characteristic of the d-d transition of Mn²⁺,its luminous intensity is weak.Therefore,on the basis of single-doped Mn²⁺,Ce³⁺/Mn²⁺co-doped SF glass was prepared to solve this problem.The results show that through the energy transfer between Ce³⁺/Mn²⁺,Ce³⁺/Mn²⁺co-doped glass obtains a wider spectrum of emission,ranging from 380-780nm,covering the visible light region.In addition,compared to SF glass doped with Mn²⁺alone,the luminescence intensity of Mn²⁺ions is increased by 3 times.By adjusting the doping concentration of Mn²⁺,the energy transfer efficiency from Ce³⁺to Mn²⁺is increased from 12.5%to 24.2%.In addition,by accurately controlling the Ce³⁺/Mn²⁺concentration ratio(0.1wt%Ce³⁺and 1.2wt%Mn²⁺),white light emission can be obtained,and the CIE coordinates are（0.333,0.343）.3、In response to the problem of divergence and poor quality of the LED light source beam,and the low efficiency of coupling with the optical fiber.The coupling system design of LED light source and optical fiber was carried out through ZEMAX.The power density of the spot converged into the fiber can reach 988.3447W/cm²,the obtained power is 0.103W,and the theoretical coupling efficiency can reach 10.3%.