Tuning Thermal Conductivity and Electron-Phonon Interactions in Carbon and Boron Nitride Moir\'e Diamanes via Twist Angle Manipulation

TL;DR

This study explores how twist angle manipulation in boron nitride and carbon Moiré diamanes affects their thermal conductivity and electron-phonon interactions, revealing significant property tunability for advanced applications.

Contribution

It provides new insights into the impact of twist angle on LTC and band gap renormalization, highlighting the role of structural disorder and quantum nuclear effects.

Findings

LTC decreases by 4.5-9 times with increased twist angle due to disorder.

20-40% difference in LTC values from different calculation methods highlights anharmonic effects.

High phonon frequencies from hydrogen bonds cause notable band gap renormalization.

Abstract

We have investigated the effect of interlayer twist angle on lattice thermal conductivity (LTC) and band gap renormalization in boron nitride and carbon Moir\'e diamanes. Moment tensor potentials were used for calculating energies and forces of interatomic interactions. The methods based on the solution of Boltzmann transport equation (BTE) for phonons and the GreenKubo (GK) formula were utilized to calculate LTC. The 20-40 % difference in LTC values obtained with GK and BTE-based methods showed the importance of high-order anharmonic contributions to LTC. Significant reduction (by 4.5 - 9 times) of the in-plane LTC with the twist angle increase caused by the growth of structural disorder was observed in the Moir\'e diamanes. This growth of disorder also leads to higher band gap renormalization (induced by classical nuclei motion) in the structures with higher twist angles. Significant band gap renormalization values obtained considering the quantum nuclear effects are caused by the high phonon frequencies related to the bonds with hydrogen atoms on the Moir\'e diamanes surfaces. Understanding of the twist angle effect on LTC and electron-phonon coupling in the Moir\'e diamanes provides a fundamental basis for manipulating their thermal and electronic properties, making these materials promising for thermoelectrics, microelectronics and optoelectronics.