High thermal conductivity of carbon allotropes and its relationship with mechanical properties: A first-principles study

Abstract

To date, many carbon allotropes have been proposed theoretically or/and experimentally, and a variety of attractive chemical and physical characters have been uncovered in these materials simultaneously. Although these researches have been abundant, there is still a lack of systematic studies on thermal transport properties of various carbon allotropes. In this paper, the lattice thermal conductivity κL of all common carbon allotropes with different crystal systems, such as diamond, bct-C4, bct-C8, hex-C, kagome, m-carbon, pentadiamond, t-carbon and w-carbon, has been investigated systematically through the combination of first-principles calculations with compressive sensing techniques and Boltzmann transport theory. In order to reveal the correlated factors of the heat transport, the mechanical properties of these carbon allotropes are also calculated. Strikingly, our results indicate that the κL are proportional to bulk modulus in these carbon allotropes with different crystal structures, which can be used to estimate thermal conductivity of carbon allotropes and may also be employed as the useful guides in future thermoelectric device designs. These findings show that this methodology can be used as a highly effective tool to estimate the lattice thermal conductivity of different semiconductor materials in thermal management system.