| AlGaN-based deep ultraviolet laser diodes(DUV-LD)not only have great application potential in many fields such as chemical analysis,dangerous goods detection,biomedicine,high-density data storage,sterilization medical treatment and material processing,but also can effectively to replace toxic and inefficient gas lasers and mercury lamps.Therefore,it has attracted worldwide attention.However,there are still many problems to be solved in the development of AlGaNbased deep ultraviolet LD at this stage.For example,because the activation energy of Mg is relatively high in p-type AlGaN,the mobility of holes is low,and the efficiency of hole injection into the active layer is very low.Second,there is electron leakage in the active region,and the leaked electrons can recombine with holes in the p-type layer,which can negatively affect the performance of the laser.Therefore,in order to improve the power and internal quantum efficiency,many research groups have improved the performance of LD by adopting different device structures.This paper mainly designs a deep-ultraviolet laser with a lasing wavelength of 280 nm and excellent performance,and further uses the Lastip software of Crosslight Company to study its p-region,and uses a series of numerical values to conduct simulation calculations and adjust the overall structural parameters of the device.,a new LD structure with more superior performance is proposed,that is,a p-type superlattice-doped AlGaN-based DUV-LD that changes the Al composition,and the traditional p-type AlGaN layer of the electron blocking layer(EBL)is changed by changing its potential barrier.The Al composition is designed as a p-type superlattice doped layer,and then compared with the DUV-LD of the traditional structure,the performance and internal physical mechanism of the LD device with the superlattice structure are studied and compared.The main content of this dissertation has the following three parts:1.Firstly,the light-emitting mechanism and basic properties of AlGaN-based DUVLEDs are briefly introduced by analyzing the reported topics,and then the application prospects,main problems and main solutions in the current market are discussed.Then it introduces the simulation method of this paper,mainly introduces the workflow of Lastip software,the types of semiconductor devices it can simulate and the establishment of the simulation environment.2.The p-type doping of AlGaN-based DUV-LDs is studied.In order to reduce the electron leakage generated by DUV-LDs in the p-region,according to the working principle of deep ultraviolet lasers,combined with and imitating the superlattice structure,a well-stepped EBL is proposed.Laser,using Lastip software to build three different electron blocking layers LD,corresponding to rectangular electron blocking layer(A),stepped electron blocking layer(B)and well stepped electron blocking layer(C),respectively.Compared with the existing EBL structure,it is concluded that the well-type stepped EBL laser with similar superlattice p-type doping has the best effect of reducing electron leakage.By comparing the luminous power,electric field strength,internal quantum efficiency,and radiation recombination rate The performance of various aspects such as energy band structure diagram has been improved.3.The p-type doping of superlattice was studied on the basis of well-stepped EBL laser,and different LDs were constructed by using Lastip software,which were compared with the existing double-sided stepped graded superlattice electron blocking layer(DSGS).Analysis,that is,the well stepped structure is changed to 98%,94%and 90%by changing its Al composition.Then,simulation calculations were carried out for different structures,and it was found that the effect of superlattice EBL on electron leakage was significantly higher than that of LD of trapped stepped EBL.In the source region,the output performance of the device is significantly better. |
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