Study On Performance Optimization And Energy Transfer Mechanism Of High Power LED

Light Emitting Diode(LED)has many advantages,such as energy-saving,environmental protection,low cost,and long lifetime,which has attracted researchers' extensive attention in recent years.However,the luminous performance and heat dissipation performance of LED are still at a low level,and its internal energy transfer mechanism has not been clearly explained.To solve the above problems,the photoelectric properties of Ga N were studied and optimized in this paper,which is of guiding significance to improve the LED luminous performance.The phase change characteristics of liquid film on the high power LED substrate were studied,which provides a reference for enhancing the heat dissipation performance of the high power LED and promoting the efficient transmission of energy.The main research contents and conclusions are as follows:(1)Study on the optoelectronic properties of Ga N.A computational model of ideal Ga N and doped Ga N: Al,In was constructed,and the electronic structure and optical properties of ideal Ga N and doped Ga N: Al,In were investigated by using the first principle calculations method.The calculation results show: ideal Ga N and doped Ga N: Al,In are direct band gap semiconductors.Al and In co-doping will cause a decrease in the band gap value of Ga N,whose decrease was 12.66%,making it suitable for the manufacture and use of LED corresponding to the emission wavelength.Compared with ideal Ga N,the absorption peak of Al and In co-doping Ga N shifts to the lower energy region,and the absorption intensity of the central absorption peak is reduced by 23.6%.The decrease in the absorption intensity of Ga N after Al and In co-doping will reduce the self-loss during the chip's light-emitting process and help improve the light-emitting efficiency of the LED.(2)Study on the liquid film's evaporation characteristics on the high power LED substrate.Efficient evaporation of the liquid film can improve the heat transfer performance of the heat dissipation substrate.The molecular dynamics method was used to study the influence of the substrate surface characteristics and the thickness of the liquid film on the liquid film's evaporation process.The research results show that the increase in the thickness of the liquid film on the substrate's surface will inhibit the liquid film's evaporation process,thereby affecting the heat transfer performance between the solid-liquid interface.The enhancement of heat transfer performance can be achieved by increasing the liquid film's heat absorption rate.In the same liquid film thickness,increasing the surface roughness can increase the liquid film's heat absorption rate and enhance the substrate's heat transfer performance.Simultaneously,the synergistic effect of surface wettability and surface roughness on heat transfer performance was considered,the heat absorption rate was increased by 11.64% at most.The liquid film's heat absorption rate on the gradient wettability surface increased significantly,whose increase was 26.37%.And the gradient wettability surface was constructed by increasing the roughness' s hydrophilicity.(3)Study on the liquid film's boiling characteristics on the high power LED substrate.For high-temperature heat dissipation surfaces,boiling heat transfer is a phase change method that can quickly cool down.Molecular dynamics simulation was used to study the boiling process of liquid film on the surface of high temperature LED substrate,mainly considering the effect of surface temperature and surface wettability on the liquid film's boiling characteristics.The research results show that:under the same temperature condition,the hydrophilic surface is more conducive to heat transfer than the hydrophobic surface,and the onset time of rapid boiling is shortened;under the same wettability condition,the liquid film has a critical temperature value for the transition from evaporation to rapid boiling.When the surface temperature is higher than the critical temperature,the liquid film will boil quickly.When the surface temperature is lower than the critical temperature value,the surface's heat transfer efficiency can be improved by increasing the surface hydrophilicity.This study obtains guidance for improving the luminescence and heat dissipation performance of high power LEDs and contributes to an in-depth understanding of their internal energy transfer process,providing a basis for developing high power LEDs.