AlGaN紫外激光器量子垒层和n型波导层设计优化

Design Optimization of Quantum Barrier and n-Type Waveguide Layers of AlGaN Ultraviolet Laser

为提高紫外激光器的光电性能,降低阈值电流,提出采用Al组分渐变的量子垒层(QBs)以及Al组分渐变的n型波导层(n-WG)优化标准结构——参考实验样品设计的AlGaN基紫外激光器结构,使用PICS3D仿真软件,对3种不同的新结构及标准结构进行构建和数值分析。比较了4种结构的L-I-V特性曲线、能带结构、载流子电流密度分布等性质,结果表明,同时采用Al组分渐变的QBs以及Al组分渐变的n-WG的紫外激光器具有更优异的性能:在800 mA注入电流下光输出功率可达775 mW,与标准结构相比提高了35.7%;阈值电流为62.3 mA,与标准结构相比降低了73.6%。

To improve the photoelectric performance of an ultraviolet laser and reduce the threshold current obtained for standard structures,AlGaNbased ultraviolet laser diodes with an Alcomposition graded quantum barrier layer(QBs)and an Alcomposition graded ntype waveguide layer(nWG)are proposed.A standard structure is extracted and modified from an experimental sample.Three different new structures and the standard structure are constructed and numerically investigated using PICS3D simulation software.A comparison of the LIV characteristic curves,band structures,carrier current density distribution,and other properties of the four structures demonstrates that ultraviolet laser diodes with an Alcomposition graded QBs and Alcomposition graded nWG exhibit improved performance.Under 800 mA injection current,the optical output power can reach 775 mW,which is 35.7%higher than that obtained for the standard structure;the threshold current decreases to 62.3 mA,which is 73.6%lower than that obtained for the standard structure.