论文标题
通过完全自动化的语音限制迁移率的计算评估放松时间近似的质量
Assessing the quality of relaxation-time approximations with fully-automated computations of phonon-limited mobilities
论文作者
论文摘要
现在，可以从第一原理电子偶联计算中常规获得载体的迁移率，从而受到散射的限制。但是，到目前为止，大多数计算都取决于基于自能，动量或恒定松弛时间近似的某种形式的线性化玻尔兹曼传输方程的简化。在这里，我们开发了高通量基础架构和自动工作流程，并计算了半导体中的69个声子限制的迁移率。我们将诉讼的结果与精确的迭代解决方案进行比较。我们得出的结论是，近似值可能与确切的值显着偏离，因此不可靠。考虑到最小的计算开销，我们的工作鼓励依靠这种精确的迭代解决方案，并警告使用放松时间近似报告的早期结果可能不准确。
The mobility of carriers, as limited by their scattering with phonons, can now routinely be obtained from first-principles electron-phonon coupling calculations. However, so far, most computations have relied on some form of simplification of the linearized Boltzmann transport equation based on either the self-energy, the momentum- or constant relaxation time approximations. Here, we develop a high-throughput infrastructure and an automatic workflow and we compute 69 phonon-limited mobilities in semiconductors. We compare the results resorting to the approximations with the exact iterative solution. We conclude that the approximate values may deviate significantly from the exact ones and are thus not reliable. Given the minimal computational overhead, our work encourages to rely on this exact iterative solution and warns on the possible inaccuracy of earlier results reported using relaxation time approximations.
