Study On The Spectrum Regulation And Stability Of Quantum Dot Photoluminescence White LED Devices

As a quasi-zero-dimensional nano-semiconductor material,quantum dot has unique light emitting properties.For example,the excitation spectrum has a wide range,the emission spectrum is narrow and symmetrical,and it has a large Stokes shift.Therefore,the use of quantum dot instead of traditional phosphors as down conversion materials to prepare white LED has broad development prospects.However,there are still many challenges in the packaging of current quantum dot converted LED.First,poor quantum dot stability,catalyst poisoning effects,low reliability of oxygen and moisture can cause quantum dot to reunite and reduce the luminous efficiency.The stability and optical quality of LED devices are reduced.In order to improve the stability and reliability of quantum dot and their LED devices,in this paper,Cd Se/Zn S quantum dot/silica gel composite films are used as experimental objects.Two kinds of white LED devices with different structures are prepared and their spectra are adjusted in combination with YAG:Ce³⁺yellow phosphor.And the current stability,temperature stability and reliability of LED device are studied.Thereby the light efficiency and stability of the quantum dot white LED device are improved.Secondly,LED chips and quantum dot will generate a lot of heat during operation.As a result,the luminous efficiency of the device decreases and the operating temperature increases.At the same time,the heat will in turn cause the quantum dot device to decay,resulting in a further reduction in the luminous efficiency of the device and a further increase in operating temperature.In order to explore the temperature distribution of LED devices with different packaging structures,the methods and principles of generating light and heat,adjust the packaging structure more accurately to reduce the operating temperature and improve the thermal stability of the device.This article uses Cd Se/Zn S quantum dot LEDs as the research object,and the device was subjected to ANSYS Workbench steady-state thermal simulation and infrared thermal imaging temperature test to explore the effect of different packaging structures on the operating temperature of the LED device and the causes of the temperature difference of the device.Therefore,LED packaging methods with high luminous efficiency,high stability and low operating temperature are proposed.In addition,in the current spectral control of copper nanoclustered white LED devices,the blue wavelength band is before 450nm,which has a potential harm to the human eye and is not conducive to the practical application of copper nanoclustered white LED.In order to adjust the spectral structure of copper nanoclusters white LED and eliminate the potential harm of short-wave blue light,in this paper,based on the use of self-assembled copper nanocluster,combined with Zn Se/Zn S quantum dot and In P quantum dot,the White LED with a blue band at 460nm was prepared,and its current stability was further evaluatedand.It provides a reference for the application of copper nanocluster in white LED.In summary,this article prepared Cd Se/Zn S quantum dot/silica film white LEDs with different packaging structures,and improved its optical performance and stability;the effect of light and heat coupling on the thermal stability of Cd Se/Zn S quantum dot white LEDs with different packaging structures was explored,and a more reasonable packaging method is proposed;finally,the spectral structure of the non-toxic and environmentally friendly copper nanocluster white LED is adjusted,and its current stability is evaluated.