Simulation Research On Barrier Layer Structure Of AlGaN Semiconductor Laser

As technology continues to advance,semiconductor lasers in the deep ultraviolet band are expected to be used in optical storage,military medical,satellite communications,sterilization,analytical instruments and other fields.In the context of the global new crown epidemic,deep UV becomes another effective means to kill the new crown virus,and the high power deep UV laser provides the possibility to kill the germs quickly in a short time.At present,the main material of deep-ultraviolet semiconductor laser is AlGaN,which is a ternary compound composed mainly by regulating the content of AlN and GaN materials,and the material can cover the whole deep-ultraviolet wavelength range.However,the application of this material is still in the laboratory research stage,mainly because the limitation of material epitaxy technology leads to high quality AlGaN thin film is difficult to prepare;the high activation energy of Mg as dopant leads to p-type doping hole activation difficulties;the high mobility of electrons easily overflow the active region leading to serious electron leakage;the polarization effect between the heterojunction leads to the aggregation of carriers,etc.,the limitation of The development of high-performance AlGaN-based deep-ultraviolet lasers is limited.In this thesis,the starting point is to improve the performance of deep-ultraviolet semiconductor lasers,focusing on reducing the polarization effect between heterojunctions and the electron leakage in the active region in the device,so as to improve the overall performance of the device.The main ideas and innovations are as follows.1.For improving the electron leakage suppression ability of the electron blocking layer by reducing the polarization effect between the active region and the electron blocking layer.The p-type embedding layer is used to repair the energy band bending between the active region and the electron-blocking layer due to the polarization effect,which increases the effective barrier height of the electron-blocking layer and significantly strengthens the ability for electron leakage,making the device’s slope efficiency and radiation compound rate significantly improved.2.On the basis of embedded p-type,AlN is used as the electron-blocking layer material for the first time,and the effect of the width of the AlN material electron-blocking layer on the performance of the laser is studied.It is found that the suppression ability of electron leakage and radiation compound rate of AlN electron blocking layer embedded with p-AlGaN material are significantly improved.3.In order to improve the radiative recombination rate of carriers in the active region,a convex quantum barrier structure is proposed to optimize the wave function of electrons and holes.Through simulation,it is found that the radiative recombination rate of the device is significantly improved.The device performance is optimized.4.A new quantum well material structure of B_0.42Ga_0.58N/B_0.47Ga_0.53N is proposed for BGaN as an active region semiconductor material.Through the simulation calculation of the basic structure of this material,it is found that the radiation compound rate of the semiconductor laser of BGaN material is approximately more than twice that of the semiconductor laser of AlGaN material.The remaining output characteristics are also significantly improved.