Simulation Research On Active Area Structure Of 280nm AlGaN Semiconductor Laser

Over the past few years silicon carbide(SiC)and gallium nitride(GaN)had been used as the third generation semiconductor materials because of their excellent properties,such as large band gap,high saturation mobility,and strong radiation resistance.The photoelectric field drew attention from all overthe world,one of them is the gallium nitride-based(GaN)materials are used as direct bandgap semiconductor materials and have a wide range of applications in optical device fabrication due to their higher luminous efficiency,such as light emitting diodes(LEDs),laser diodes(LD),UV detectors and so on.And by adjusting its alloy composition,a bandgap width of 0.77 eV(InN)-6.28 eV(AlN)can be continuously adjusted to cover all wavelength ranges of visible light.With the continuous technological innovation,various wavelength bands of light emitting diodes and laser devices have been successfully prepared.Recently,there is an increasing interest on relatively less mature UV AlGaN-based semiconductor laser diodes(UV-LDs)as a high-intensity light source.Since AlGaN deep ultraviolet lasers have a variety of applications in biological reagent detection,high-density optical data storage,ultraviolet astronomy,photolithography,medical sterilization,and chemical/biological analysis.However,it is difficult to obtain high-quality AlGaN materials due to limitations of epitaxial growth techniques;also high activation energy of Mg dopants leads to a limited P-type doping efficiency.Moreover,arelatively low holes injection and large amount of electron leakage causes some problems such as: unsatisfactory laser luminous efficiency hinder the superior performance of AlGaN deep ultraviolet lasers.Accordingly,this article researches the deep ultraviolet semiconductor laser based on AlGaN.After the physical basis had been analyzed for the semiconductor lasers,a model was established and related parameters were calculated.Thus,a semiconductor deep-ultraviolet laser diode with a wavelength of 280 nm was designed and optimized.The focus was at the design and optimization of quantum well structures in active regions,including the effects of quantum well layers,quantum well potential wells,and barrier thickness on the output performance of the laser,and the aforementioned problems were investigated via different mechanisms.The final computational simulations show that when the number of quantum well layers in the active region is two,and the barrier thickness of the well is 3 nm and 8 nm,the device performance is the best.The threshold current is 38.78 mA and the slope efficiency is 0.776 W/A.Also the polarization phenomena existing in the AlGaN material had been considered,in order to reduce the effect of this phenomena on the laser performance for increase the output.The existing improvement methods were compared and analyzed,and a new type of structure was proposed.The improved new structure threshold current is 33.08 mA,which is 14.7% lower than the original structure.The slope efficiency of the laser is 0.8145W/A,which is 4.73% higher than the original structure,and the device performance is obviously improved.