GaAs/AlGaAs太赫兹量子级联激光器的热分析

Thermal analysis of GaAs/AlGaAs terahertz quantum cascade lasers

为研究太赫兹量子级联激光器(THzQCLs)中的热传输及有效散热方法,建立了二维/三维有限元热分析模型,模拟计算了GaAs/AlGaAs THz QCLs低温工作时的温度及热流分布;并讨论了源区结构参数、热沉材料及散热膜层对器件热传输的影响规律。研究结果表明,器件源区温度水平方向分布较均匀,垂直方向温差大,源区热量主要依靠热沉导出;减小源区厚度、增加腔长与减小脊宽均有利于促进热传导并降低源区温度;在器件顶部增加AlN薄膜具有显著的辅助散热效果,当薄膜厚度大于8μm时,源区温降趋于缓慢。

The 2 D/3 D Finite Element(FE) heat dissipation model is established for calculating the temperature distribution and heat flux of GaAs/AlGaAs Terahertz Quantum Cascade Lasers(THz QCLs) in order to investigate the thermal transfer process and effective heat dissipation methods. The influences of device geometry, heat sink materials and AlN film on thermal properties of THz QCLs are studied. The results show that the horizontal temperature distribution of active region is uniform, while the perpendicular temperature difference is high. The heat generated in active region is mainly transmitted by the heat sink. Thinning the active region, increasing the cavity length and narrowing the ridge width facilitate the heat dissipation and decrease the temperature of the active region. Adding AlN films on top of the device shows a significant auxiliary heat dissipation effect. Especially, when the thickness of the film is greater than 8 μm, the drop in temperature of the active region tends to be slow.