The synergistic modulation of electronic and geometry structures leads to ultra-low thermal conductivity of graphene-like borides (g-B3X5, X=N, P, As)

TL;DR

This paper introduces a synergy strategy combining geometric and bonding modifications to design 2D borides with ultra-low thermal conductivity, promising for advanced thermal management in lightweight devices.

Contribution

It proposes a novel component reconstruction strategy to achieve ultra-low thermal conductivity in graphene-like borides through electronic and geometric synergy effects.

Findings

g-B3N5 exhibits thermal conductivity of 21.08 W/mK.

g-B3P5 and g-B3As5 have thermal conductivities of 2.50 and 1.85 W/mK.

Synergy effect softens acoustic branches and suppresses scattering processes.

Abstract

The design of novel devices with specific technical interests through modulating structural properties and bonding characteristics promotes the vigorous development of materials informatics. Herein, we propose a synergy strategy of component reconstruction by combining geometric configuration and bonding characteristics. With the synergy strategy, we designed a novel two-dimensional (2D) graphene-like borides, e.g. g-B3N5, which possesses counter-intuitive ultra-low thermal conductivity of 21.08 W/mK despite the small atomic mass. The ultra-low thermal conductivity is attributed to the synergy effect of electronics and geometry on thermal transport due to the combining reconstruction of g-BN and nitrogene. With the synergy effect, the dominant acoustic branches are strongly softened, and the scattering absorption and Umklapp process are simultaneously suppressed. Thus, the thermal conductivity is significantly lowered. To verify the component reconstruction strategy, we further constructed g-B3P5 and g-B3As5, and uncovered the ultra-low thermal conductivity of 2.50 and 1.85 W/mK, respectively. The synergy effect and the designed ultra-low thermal conductivity materials with lightweight atomic mass cater to the demand for light development of momentum machinery and heat protection, such as aerospace vehicles, high-speed rail, automobiles.