Enhanced thermoelectric properties in hybrid graphene-boron nitride nanoribbons

TL;DR

This study demonstrates that embedding hexagonal boron nitride into graphene nanoribbons significantly enhances their thermoelectric efficiency, making them promising for high-performance thermoelectric devices.

Contribution

The paper introduces a novel hybrid graphene-boron nitride nanoribbon design that greatly improves thermoelectric properties compared to pristine graphene nanoribbons.

Findings

ZT enhanced up to 10-20 times in armchair BCNNRs

ZT increased 2-3 times in zigzag BCNNRs

Thermoelectric improvement due to increased Seebeck coefficient and reduced thermal conductivity

Abstract

The thermoelectric properties of hybrid graphene-boron nitride nanoribbons (BCNNRs) are investigated using the non-equilibrium Green's function (NEGF) approach. We find that the thermoelectric figure of merit (ZT) can be remarkably enhanced by periodically embedding hexagonal BN (h-BN) into graphene nanoribbons (GNRs). Compared to pristine GNRs, the ZT for armchair-edged BCNNRs with width index 3p+2 is enhanced up to 10~20 times while the ZT of nanoribbons with other widths is enhanced just by 1.5~3 times. As for zigzag-edge nanoribbons, the ZT is enhanced up to 2~3 times. This improvement comes from the combined increase in the Seebeck coefficient and the reduction in the thermal conductivity outweighing the decrease in the electrical conductance. In addition, the effect of component ratio of h-BN on the thermoelectric transport properties is discussed. These results qualify BCNNRs as a promising candidate for building outstanding thermoelectric devices.