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采用非平衡格林函数方法研究了嵌入有限长、半无限长、无限长线型缺陷的锯齿型石墨纳米带(ZGNR)的热输运性质.结果表明,缺陷类型和缺陷长度对ZGNR的热导有重要影响.当嵌入的线型缺陷长度相同时,包含t5t7线型缺陷的石墨纳米带比包含Stone-Wales线型缺陷的条带热导低.对于嵌入有限长、同种缺陷的ZGNR,其热导随线型缺陷的长度增加而降低,但是当线型缺陷很长时,其热导对缺陷长度的变化不再敏感.通过比较嵌入有限长、半无限长、无限长线型缺陷的ZGNR,我们发现嵌入无限长缺陷的条带比嵌入半无限长缺陷的条带热导高,而后者比嵌入有限长线型缺陷的条带热导高.这主要是因为在这几种结构中声子传输方向的散射界面数不同所导致的.散射界面越多,对应的热导就越低.通过分析透射曲线和声子局域态密度图,解释了这些热输运现象.这些研究结果表明线型缺陷能够有效地调控石墨纳米带的热输运性质.
The thermal transport properties of zigzag-type graphite nanoribbons (ZGNRs) embedded in finite length, semi-infinite length and infinity long-line defects were investigated by using the non-equilibrium Green’s function method. The results show that the type of defects and the length of defect are important for the thermal conductivity of ZGNR .When the length of embedded linear defects is the same, the graphite nanoribbons containing t5t7 linear defects have a lower thermal conductivity than those containing the Stone-Wales linear defects.For the ZGNR embedded with finite length and same defects, the thermal conductivity However, when the linear defects are long, their thermal conductivity is no longer sensitive to the variation of defect length. By comparing the ZGNR with finite length, semi-infinite length and infinite length linear defects, we find that Bands embedded in infinitesimal defects are higher than those embedded in semi-infinity defects, which are higher than the thermal conductivity of the stripe embedded in the finite-length defects, mainly because the phonon transport direction in these structures The number of scattering interfaces is different, the more the scattering interface is, the lower the corresponding thermal conductance.These heat transport phenomena are explained by analyzing the transmission curves and the phonon state-density maps.These results show that the linear defects Be efficiently regulate the heat transport properties of graphite nanoribbons.