Study Of The GaN-based Laser Diodes By Adjusting InGaN Quantum Barriers

Gallium Nitride(GaN)-based semiconductor lasers(LDs)have the advantages of long life,low cost and light weight,and are widely used in laser light sources,data storage,full-color display and other industries.Although GaN-based LDs have been commercialized,there are still problems such as excessive threshold current and low efficiency.Among them,polarization effect and carrier leakage are considered to be the main factors that affect their optoelectronic properties.In this paper,the quantum barrier regulation of InGaN is hoped to improve the optoelectronic properties of GaNbased LDs by reducing the polarization effect of the active region and improving its confinement capability for carriers.The specific work is as follows:1.Introducing In into the traditional GaN barrier to form an InxGa1-xN barrier,and regulating the In composition in the barrier.The research results show that with the increase of In composition in the barrier,the threshold current of the device decreases gradually,and the slope efficiency first increases and then decreases.This is because the introduction of In in the barrier structure makes the barrier more matched with the lattice constant of the InGaN quantum well,and with the increase of the In composition in the barrier,the polarization charge in the active region decreases,and the quantum confinement stark effect is reduced;however,since the band gap of InGaN material is lower than that of GaN material,and with the increase of In composition in the barrier,the height of the quantum well barrier decreases,which is not conducive to confine the carriers in the active region,the carrier leakage also increased.2.On the basis of the above research,in order to reduce the polarization effect in the active region without reducing the carrier confinement ability in the active region,an InGaN-GaN-InGaN(IGI)triangular barrier structure is designed.The research results show that the device has the lowest threshold current and the highest slope efficiency compared with the GaN barrier and InGaN barrier after adopting the IGI triangular barrier structure.This is because the IGI triangular barrier structure,compared with the InGaN barrier structure,can ensure that the barrier height is consistent with the traditional GaN barrier height,so that the carrier confinement capability in the active region will not be reduced;in addition,the use of this barrier Finally,compared with the GaN barrier,the contact interface between the barrier layer and the InGaN quantum well layer is an InGaN-InGaN interface,which can effectively reduce the polarization effect in the quantum well.3.On the basis of the above research,the In composition of the IGI triangular barrier structure was regulated,and its influence on the performance of GaN-based LD was studied.The results show that with the increase of the In composition of the IGI triangular barrier structure,the threshold current of the device decreases gradually,and the slope efficiency first increases and then decreases.This is because with the increase of the In composition in the barrier,the polarization effect in the active region decreases,and the carrier confinement capability increases;however,when the In composition is too high,the non-radiative recombination rate of the device is significantly accelerated,and the output Power drops.