| LED(Light Emitting Diode)is a kind of semiconductor electronic components that can convert electrical energy into light energy.LEDs have been widely used in lighting,display,optical communication and other fields,because of their excellent photoelectric performance,such as power saving and long life.Currently,white LEDs on the market are mainly fabricated by covering a blue LED with a layer of yellow phosphor.Fluorescent conversion technology of white LED has the disadvantages of low conversion efficiency and degradation of red light band.Moreover,a significant portion of the white light is not extracted from the LEDs.Therefore,to improve LED performance,not only to improve internal quantum efficiency,but also to improve light extraction efficiency.In this thesis,the surface plasmon enhanced quantum dot LED luminescence efficiency based on CdS-CdSe quantum dots is discussed both from the aspects of numerical simulation,theoretical calculation and experimental verification.The main research contents of the thesis are as follows:Firstly,the Green's function integration method is introduced in detail,and combined with the advantages of Green's function integration method and finite element technology,a method for calculating the scattering of single scatterer more efficiently and accurately is proposed.Secondly,after extracting the electromagnetic dipole from the scattering field of the single particle obtained by the above method,the point dipole theory is proposed to solve the electromagnetic response of the periodic lattice in the optical multilayer thin film system.Provide a theoretical basis for the periodic plasma lattice to improve the light extraction efficiency of solid-state lighting systems.Then,the optical properties of colloidal quantum dots and their unique advantages in LED lighting applications are introduced.The general structure and several improved structures of colloidal quantum dot LEDs are analyzed.Finally,the synthesis and transfer of gold nanoparticles in the experiment were studied,and the local surface plasmon effect of noble metal nanoparticles and the principle of enhancing the luminescence of fluorescent molecules were described.Adjusting the position of gold nanoparticles and quantum dots in the LED structure,optimizing the coupling efficiency between local surface plasmon and quantum dots,measuring the fluorescence spectrum and time-resolved fluorescence spectrum of the system,and verifying the regulation of gold nanoparticles on quantum dot fluorescence enhancement. |
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