Tunable thermoelectric properties in bended graphene nanoribbons

• 作者: 何军 方卯发 潘长宁
• 来源期刊: 中国物理B（英文版）
• 关键词: graphene nanoribbons thermoelectric properties quantum interference effect
• 年，卷（期）: 2016,（7）
• 页码范围: 078102-1-078102-7
• 页数: 1页
• 语种: 英文
• DOI: 10.1088/1674-1056/25/7/078102

摘要

The ballistic thermoelectric properties in bended graphene nanoribbons (GNRs) are systematically investigated by using atomistic simulation of electron and phonon transport. We find that the electron resonant tunneling effect occurs in the metallic–semiconducting linked ZZ-GNRs (the bended GNRs with zigzag edge leads). The electron-wave quan-tum interference effect occurs in the metallic–metallic linked AA-GNRs (the bended GNRs with armchair edge leads). These different physical mechanisms lead to the large Seebeck coefficient S and high electron conductance in bended ZZ-GNRs/AA-GNRs. Combined with the reduced lattice thermal conduction, the significant enhancement of the figure of merit ZT is predicted. Moreover, we find that the ZTmax (the maximum peak of ZT) is sensitive to the structural parameters. It can be conveniently tuned by changing the interbend length of bended GNRs. The magnitude of ZT ranges from the 0.15 to 0.72. Geometry-controlled ballistic thermoelectric effect offers an effective way to design thermoelectric devices such as thermocouples based on graphene.