Healing defective CVD-graphene through vapor phase treatment

Abstract

Structural defects present on chemical vapor deposition (CVD)-graphene have usually originated from the growth stage and transfer process. They limit the electronic transport properties of graphene and degrade performance of related devices. Here we report that these inherent atomic defects could be selectively healed by a simple vapor phase treatment performed in equipment conventionally used for atomic layer deposition (ALD). The unique chemistry of Al2O3 ALD facilitated selective depositions of AlxOy compounds on the defects, which could be readily probed and visualized using AFM imaging. The healing agent, AlxOy, was observed to bind tightly to the defects and lead to doping of the CVD-graphene, which was reflected in the noticeable improvement in electrical sheet resistance. In contrast with the chemically doped graphene, the ALD-treated graphenes revealed notable long-term stability under environmental conditions. Our approach promises selective healing of defects present in most materials and possibly ensures considerable improvement in electrical and mechanical properties. ALD with a broad spectrum of material selection could be a versatile tool for upgrading properties of materials.