论文标题
Fano共振引起的双层石墨烯结构中的热电特性的增强
Enhancement of the thermoelectric properties in bilayer graphene structures induced by Fano resonances
论文作者
论文摘要
双层石墨烯的FANO和混合共振可能对热电设备有吸引力。此类共振提出的特殊曲线可以显着增强塞贝克系数和功率因数。在这项工作中,我们研究了双层石墨烯单和双屏障结构的热电特性。电荷载体被描述为通过有效的狄拉克样哈密顿素化的大量手性颗粒。混合矩阵法,Landauer-Büttiker形式主义和Cutler-Mott公式分别实施以获得传输,运输和热电特性。分析了无间隙和间隙的单屏障和凹陷的塞贝克系数和功率因数。我们发现,在发生FANO共振的能量范围内,Seebeck系数可达到数十MV/K的值,并且功率因数达到NW/K阶的值。混合谐振还具有热电特性的高值,但是不如FANO共振高。我们还发现,尽管FANO和混合轮廓表现在间隙屏障结构的电导率中,但随着带隙变大,Seebeck系数和功率因数会系统地降低。因此,我们的发现表明,双层石墨烯屏障结构可用于改善热电设备的响应。
Fano and hybrid resonances of bilayer graphene could be attractive for thermoelectric devices. The special profile presented by such resonances could significantly enhance the Seebeck coefficient and the power factor. In this work, we study the thermoelectric properties of bilayer graphene single and double barrier structures. The charge carriers are described as massive chiral particles through an effective Dirac-like Hamiltonian. The Hybrid matrix method, the Landauer-Büttiker formalism and the Cutler-Mott formula are implemented to obtain the transmission, transport and thermoelectric properties, respectively. The Seebeck coefficient and the power factor are analyzed for gapless and gapped single and double barriers. We find that in the energy range where Fano resonances occur, the Seebeck coefficient attains values of tens of mV/K and the power factor reaches values of the order nW/K. Hybrid resonances also sustain high values for the thermoelectric properties, however not as high as Fano resonances. We also find that despite the Fano and hybrid profiles are manifested in the conductance of gapped barrier structures, the Seebeck coefficient and the power factor are systematically reduced as the bandgap gets larger. So, our findings indicate that bilayer graphene barrier structures can be used to improve the response of thermoelectric devices.