Research On Key Technologies Of ALGaInP Red LED Epitaxial Wafer

Light Emitting Diode(LED)are widely used in various fields such as display and illumination in photovoltaic energy sources.Many companies in China are producing and researching.High-brightness LED made from AlGaInP materials are widely used in the industry.This thesis has carried on the more in-depth research to the key technology related to AlGaInP red light LED,through a great deal of design and experiment,choose the brightness characteristic better epitaxial growth craft and structural design,make LED luminance reach 130mcd.This thesis focuses on the study of several key technologies for improving the luminous intensity of LED.The work done is mainly in the following areas:1.The composite DBR experiment was designed to optimize the reflectivity of incident light waves with large inclination angles.Six different wavelength combinations were designed.The optimal composite DBR structure was finally selected through optimization design and test comparison.That is 620 nm*15 plus 670 nm*3.The combination of 720 nm*3 plus 770 nm*3 plus 820 nm*3 plus 870 nm*3 is used as a DBR mirror structure for a red LED device,which increases the brightness by 10%.2.In this thesis,the NP-type doping concentration experiment was designed.After 7 groups of N-doping and P-doping doping concentration experiments,it was found that the N-type doping concentration of 5e17 and the P-type doping concentration of 1e18 were optimized.Doping increases brightness by 3%.3.Quantum well thickness and logarithmic experiments were designed.Through 8 experiments with different barrier thickness,well thickness and logarithm,the total number of pairs of 2400ppm,barrier thickness 56nm,well thickness 48nm,and 21 pairs was obtained.The optimal conditions can increase brightness by 8%.4.In this thesis,an experiment to optimize the window layer was designed.Through three sets of different doped samples and the same molarity of CBr4 and CCl4,the contact layer growth rate was calculated and compared using the in-situ monitoring curve carried by MOCVD.The experiment concluded that the use of CBr4 can better control the growth of the contact layer.Through the above design and experiment,the luminance of the AlGaInP red LED has been improved by 20%,reaching the 130mcd uminance target.