Effect of environmental screening and strain on optoelectronic properties of quantum defects in two-dimensional materials*

Point defects  in two-dimensional wide band-gap materials are potential hosts for emerging quantum properties such as single-photon emitters and spin quantum bits, as building blocks for quantum information technology devices. Despite the experiment efforts on characterization of such defects, their exact chemical composition remains unknown.  Meanwhile strain and environmental screening can strongly modify the optical signature, which may be responsible for observed variation of photoluminescence in different samples.

In this work, we studied environmental screening by varying layer thickness and substrate as well as effects of strain on optoelectronic properties of quantum defects in h-BN. We apply many-body perturbation theory including accurate electron correlation and electron-hole interaction to study quasiparticle energies, optical excitation and exciton lifetime of these quantum defects. In particular, we used our reciprocal-space interpolation method for summing-up effective polarizability[1] to include substrate screening effect at GW/BSE level. Our study provides important guidance on interpolation of experimental optical signature and manipulation of optoelectronic properties of single photon emitters in layered materials.

[1] C. Guo et al, Phys. Rev. B, 102, 205113 (2021)