Non-equilibrium quantum transport theory: current and gain in quantum cascade lasers
Non-equilibrium quantum transport theory: current and gain in quantum cascade lasers
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DOI：
10.1007/s10825-007-0158-2
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发表时间：
2008-09-01
影响因子：
2.1
通讯作者：
Vogl, Peter
中科院分区：
文献类型：
--
作者：
Kubis, Tillmann;Yeh, Catherine;Vogl, Peter
我们已经开发了一个自洽的非平衡格林函数理论（NEGF），用于太z量子级联激光器（QCL）中的电荷传输和光增益，并给出了具体GaAs/Al.15Ga的I-V特性，光增益以及电流密度对温度的依赖关系的定量结果。85As QCL结构。考虑了自一致玻恩近似内的声子散射、杂质散射、Hartree电子-电子散射和界面粗糙度散射。我们表明，只要系统始终被视为开放量子系统，就可以通过考虑结构的单个周期来成功地建模QCL器件的特性。为了支持这一发现，我们开发了两种不同的数值有效接触模型，并将单周期结果与准周期NEGF计算进行了比较。两种方法均与实验结果吻合良好。
We have developed a self-consistent non-equilibrium Green's function theory (NEGF) for charge transport and optical gain in THz quantum cascade lasers (QCL) and present quantitative results for the I-V characteristics, optical gain, as well as the temperature dependence of the current density for a concrete GaAs/Al.15Ga.85As QCL structure. Phonon scattering, impurity, Hartree electron-electron and interface roughness scattering within the self-consistent Born approximation are taken into account. We show that the characteristic QCL device properties can be successfully modeled by taking into account a single period of the structure, provided the system is consistently treated as open quantum system. In order to support this finding, we have developed two different numerically efficient contact models and compare single-period results with a quasi-periodic NEGF calculation. Both approaches show good agreement with experiment as well as with one another.