Preparation And Properties Of GaN Photonic Crystal Micro-LED Chip

With the development of the third-generation semiconductor materials represented by Ga N materials,Ga N-based LEDs have developed rapidly and begun to be widely commercialized,which provides the basis for the application of visible light communication.However,the modulation bandwidth of common commercial LEDs is currently only tens of megahertz,and it cannot be adapted to the requirements of high-speed visible light communication systems in future.In order to increase the modulation bandwidth,the improvement of the LED light source part of the light emitting device still needs to be improved.fabricating the photonic crystal structure into the LED chip quantum well can affect the photon life and light propagation,which changes the modulation bandwidth and light extraction efficiency of the LED chip.utilizing the flip-chip micro-LED structure,its package volume is minimized,which makes visible light communication more flexible in various places.Therefore,it is of great significance to study the flip-chip micro-LED with photonic crystals.The thesis uses the FDTD solution to study the effect of the photonic crystal structure on the blue and green light LED models.By optimizing the parameters such as the period,radius period ratio and height of the photonic crystal structure,the Purcell factor and light extraction efficiency are simultaneously improved.In the blue light LED,when the photonic crystal period is 600 nm,the radius period ratio is 0.37,the photonic crystal height is 630 nm,the ITO thickness is 150 nm.The Purcell factor reaches 2.23,which is 197% higher than the plane chip,and the light extraction efficiency is 92%,which is 48% higher than the plane chip.In the green light LED,when the photonic crystal period is 400 nm and the radius period ratio is 0.3,the height of the nanopillar is 500 nm.The Purcell factor reaches 2.31,which is 132% higher than the plane chip,and the light extraction efficiency is 96%,which is 16% higher than the plane chip.The Purcell factor and the light extraction efficiency of the flip-chip LED with photonic crystal structure show a positive correlation change trend.In addition,blue and green light flip-chip micro-LED chips with photonic crystals were fabricated.The experimental results show that the photonic crystal structure can more effectively improve the modulation bandwidth of blue and green light LED chips.With a large current injection,the modulation bandwidth of blue light flip-chip micro-LEDs with mesa radius of 30 ?m,60 ?m,and 90 ?m can achieve 190 MHz,150 MHz and 127 MHz,which is 27%,92% and 188% higher than the plane chip,respectively;the optical power of green light flip-chip micro-LEDs with mesa radius of 30 ?m and 90 ?m can achieve 6.1 m W and 36.4 m W,which is 2% and 9% higher than the plane chip,respectively;its modulation bandwidth reached 175 MHz and 51 MHz,which is 9% and 20% higher than the plane chip,respectively;...