Thermal transport in graphene/h-BN lateral heterostructures with interface compositional diffusion

¹ School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University - 610031 Chengdu, PRC
² Functional Nano and Soft Materials Laboratory (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University - 215123 Suzhou, PRC
³ Laboratoire EM2C, CNRS, CentraleSupélec, Université Paris- Saclay - Grande Voie des Vignes, 92295 Châtenay- Malabry Cedex, France
⁴ LIMMS/CNRS- IIS(UMI2820) Institute of Industrial Science, University of Tokyo - 4-6-1 Komaba, Meguro- ku, 153-8505 Tokyo, Japan

^(a) yuxiang.ni@swjtu.edu.cn (corresponding author)

Received: 2 December 2018
Accepted: 15 February 2019

Abstract

The synthesis of two-dimensional lateral structures is often associated with compositional transition, causing graded interfaces. Our molecular-dynamics simulations show that the graded interface can significantly increase the thermal resistance of graphene/h-BN lateral heterostructures. The thermal conductivity is therefore lowered depending on the length of the interface diffusion. The phonon participation ratio calculations indicate the occurrence of phonon localization in the composition-graded heterostructures. Meanwhile, thermal rectification is observed in the graphene/h-BN lateral heterostructures, and the heat transport from h-BN to graphene is favored, particularly in the system with abrupt interface. These results provide critical information for the novel design of two-dimensional lateral heterostructures in terms of thermoelectrics and thermal diodes.