论文标题
单通道还是多通道热传输？高阶非谐校正对半导体的预测声子热传输特性的影响
Single-channel or multi-channel thermal transport? Effect of higher-order anharmonic corrections on the predicted phonon thermal transport properties of semiconductors
论文作者
论文摘要
通过考虑高阶四弹片散射，声子重归于和多通道热传输的高阶段，研究了八个金属间半导体的声子热传输性能。常用的最低阶理理论仅解释了三个子散射，而没有声子重构化，但对于考虑的材料而言，急剧失败，并低估了导热率的最高两倍。三种化合物的热导率降低，并增加了五种化合物的增加，由于对预测的导热率的四个弹片散射和声子僵硬的对比作用，因此进行了高阶校正。使用高阶理论，在300 K的温度下，BICSK2获得的最低导热率为0.31 W/m-K，而其他三种化合物（SBCSK2，SBRBNA2和SBRBK2）的导热电导率低于0.5 w/m-k的导热电导率，这是通过粒子样的唱机传输通道。在所有这些超低热导率化合物中，波状相干传输通道的贡献低于0.05 w/m-k。高阶理论是对热运输物理学的正确描述的必要条件，而失败的热传输被错误地以最低阶理论为多通道传输。
The phonon thermal transport properties of eight ternary intermetallic semiconductors are investigated by accounting for higher-order four-phonon scattering, phonon renormalization, and multi-channel thermal transport. The commonly used lowest-order theory, which accounts only for three-phonon scattering and without phonon renormalization, fails drastically for considered materials and underpredicts the thermal conductivity by up to a factor of two. The thermal conductivity decreases for three compounds and increases for five compounds with the application of higher-order corrections owing to a contrasting role of four-phonon scattering and phonon stiffening on the predicted thermal conductivity. Using the higher-order theory, at a temperature of 300 K, the lowest obtained thermal conductivity is 0.31 W/m-K for BiCsK2 and three other compounds (SbCsK2, SbRbNa2, and SbRbK2) have thermal conductivities lower than 0.5 W/m-K via the particle-like phonon transport channel. The contribution from the wave-like coherent transport channel is lower than 0.05 W/m-K in all of these ultra-low thermal conductivity compounds. The higher-order theory is a must for the correct description of thermal transport physics, failing which the thermal transport is wrongly characterized as multi-channel transport by the lowest-order theory.
