▎ 摘　　要

The ever-expanding array of two-dimensional materials and heterostructures susceptible to alteration in oxygen environments motivates the search for lateral confinement techniques outside conventional lithographic and etching methods. Laser ablation of such materials using a femtosecond pulsed Ti: Sapphire laser and programmable x-y stage is a single-step process that can be used as a flexible tool for device processing. However, scanning probe analysis of sub-micron graphene ribbons fabricated with this technique reveal considerable defect accumulation under ambient conditions. We show that such defects are largely alleviated by the simple change in the ablation environment from air to water. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement