NUS scientists discovered that a two-dimensional (2D) semiconducting material, known as black phosphorus (BP), exhibits an electronic self-passivation phenomenon by re-arranging its vacancy defects. This may potentially enhance the charge mobility of the material and its analogs.
source https://www.lifetechnology.com/blogs/life-technology-science-news/electronic-self-passivation-of-single-vacancy-in-black-phosphorus