Controllable repairing the single vacancies of BC3 monolayer using CO and BF molecules: A first-principles study

Abstract

Controllable repairing the vacancy-defects of BC3 monolayers is significantly important for their fundamental investigations and various applications. We performed first-principles calculations to present a promising strategy of controllable repairing of monovacancies in BC3 monolayer using CO and BF molecules. Two-step repairing process of C monovacancy was performed, the first of which is exposure to CO molecule that provides a C atom to fill the C vacancy, and the second step is removing the extra O atom on the BC3 monolayer via interacting with another CO molecule. In this case, a physisorbed CO2 molecule is formed and leaves the pure BC3 monolayer. However, a three-step repairing procedure for B monovacancy using BF molecule was explored, the first two steps of which are very akin to the case of C monovacancy, but the difference is the chemisorption of the BF2 molecule on the pure BC3 monolayer. We thus explored the third step to remove the BF2 molecule using heating method. At 600 K, BF2 molecule can desorb rapidly from the BC3 monolayer, while whose structural integrity remains. Our study reveals useful insight into the synthesis of perfect BC3 monolayers and presents a proposed strategy for repairing the single vacancies in BC3 monolayers.