【摘要】 基于第一性原理的方法,从原子层面上研究了锯齿型石墨烯纳米条带与碳链以及石墨烯纳米片组成的一维碳基纳米材料的自旋热电性能.研究发现在费米面处自旋向下的传输函数压抑至零,而自旋向上的传输函数大约为0.25,具有理想的半金属性质.另外声子部分热导明显小于对应的电子部分热导.同时低温区域(80 K附近)自旋Seebeck系数明显得到加强,导致了电荷和自旋热电品质因子接近40.并且在室温区域,自旋热电品质因子明显大于对应的电荷热电品质因子.更多还原

【Abstract】 Based on first-principles methods, the authors of this paper investigate spin thermoelectric effects ofone-dimensional spin-based devices consisting of zigzag-edged graphene nanoribbons(ZGNRs), carbon chainsand graphene nanoflake. It is found that the spin-down transmission function is suppressed to zero, while thespin-up transmission function is about 0.25. Therefore, an ideal half-metallic property is achieved. In addition,the phonon thermal conductance is obviously smaller than the electronic thermal conductance. Meantime, thespin Seebeck effects are obviously enhanced at the low-temperature regime(about 80K), resulting in the factthat spin thermoelectric figure of merit can reach about 40. Moreover, the spin thermoelectric figure of merit isalways larger than the corresponding charge thermoelectric figure of merit. Therefore, the study shows that theycan be used to prepare the ideal thermospin devices.更多还原