Strain Effects: Properties of Deep Defects in Hexagonal Boron Nitride

The spin states of different point defects and defect-complexes within layered semiconductors, such as hexagonal boron nitride (hBN), are of interest for different quantum applications. Using first principles-based methods, we show that strain can affect the structural, electronic and spin properties of defects such as boron and nitrogen vacancies, as well as anti-site defects within hBN monolayers. The results show that along with the defect-defect interactions, strain changes the spin-states of the defect. In particular, in the case of boron vacancy, where the unstrained structure undergoes Jahn Teller distortion, strain makes the symmetric, undistorted structure metastable. The distorted boron-vacancy defect is a spin-1/2 structure, while the symmetric structure has a net spin of 3/2. These results are promising and show that strain can be an important mechanism in manipulating the electronic and spin properties of defects in layered materials.