Structure Optimization of Multiple Quantum Wells in Near Ultraviolet Light Emitting Diodes with 380 nm Wavelength

The influence of multiple quantum wells with different barriers on the characteristics of the near ultraviolet light emitting diodes was numerically investigated.Using single GaN,single Al0.1Ga0.9N,trilaminar Al0.1Ga0.9N/Al0.15Ga0.85N/Al0.1Ga0.9N as barriers to study the characteristics of internal quantum efficiency,carriers concentration and radiative recombination rate.For trilaminar Al0.1Ga0.9N/ Al0.15Ga0.85N/Al0.1Ga0.9N barrier,choose two different thickness ratio,6 nm/8 nm/6 nm and 7 nm/6 nm/7 nm.The simulation results show that LEDs with AlGaN barriers have better performance than GaN barrier LED.For AlGaN barrier LEDs,more carriers can be confined in active region,especially hole concentration,can improve one order of magnitude approximately.The radiative recombination rate can increase 2~10 times.Compared with single AlGaN barrier LED,in trilaminar AlGaN barrier LEDs the carriers concentration is more uniform.And the radiative recombination rate increases about 7 times,the internal quantum efficiency improves 14.5%.The different thickness ratio of trilaminar AlGaN barrier LED can fine adjust the inclination of energy band,then reduce the negative effects on carriers concentration and internal efficiency caused by polarization.