Paved phonon transport route in graphene by vapor phase process

Abstract

Various atomistic defects ever-present in graphene have triggered unwanted phonon scattering, thereby significantly deteriorating the heat transport property of the graphene. Consequently, continuous endeavors have been made to minimize these atomistic defects. Here, we first experimentally show that defect healing based on atomic layer deposition (ALD) can significantly mitigate the degradation in the thermal conductivity of the graphene. After defect healing with Pt and Al2O3 ALD, the thermal conductivities of graphene synthesized by conventional chemical vapor deposition were improved by similar to 83% and similar to 64%, respectively. It is speculated that the healing atoms facilitate heat transfer across the defects, by eliminating the influence of vacancy in the graphene layer, which likely increases the phonon lifetime (leading to a noticeable improvement in thermal conductivity). This study provides an understanding of how defect engineering could affect phonon transport in 2D materials and sheds light on affordable graphene with excellent thermal conductivity.