为获得更高的阈值电压, 提出了一种新型栅下双异质结增强型AlGaN/GaN高电子迁移率晶体管(HEMT)。使用双异质结电荷控制模型分析了基本机理, 推导了阈值电压表达式。仿真结果表明, 器件阈值电压与调制层Al组分呈线性关系。当调制层Al组分小于势垒层时, 阈值电压增大, 反之减小。调制层厚度可加大这种调制作用。当调制层Al组分为0%、厚度为112 nm时, 器件具有2.13 V的阈值电压和1.66 mΩ·cm2的比导通电阻。相对于常规凹槽栅结构, 新结构的阈值电压提高了173%。

An optical bandwidth analysis of a quantum-well (16 nm) transistor laser with 150-\mum cavity length using a charge control model is reported in order to modify the quantum-well location through the base region. At constant bias current, the simulation shows significant enhancement in optical bandwidth due to moving the quantum well in the direction of collector-base junction. No remarkable resonance peak, limiting factor in laser diodes, is observed during this modification in transistor laser structure. The method can be utilized for transistor laser structure design.