Theoretical study of quantum emitters in two-dimensional silicon carbide monolayers

Abstract

The electronic and optical features of some potential single-photon sources in two-dimensional silicon carbide monolayers is studied via ab initio calculations and group theory analyses. A few point defects in three charge states (negative, positive, and neutral) are considered. By applying performance criteria, Stone-Wales defects without and with combination of antisite defects are studied in detail. The formation energy calculations reveal that neutral and positive charge states of these defects are stable. We compute the zero-phonon-line energy, the Huang-Rhys (HR) factor, and the photoluminescence spectrum for the available transitions in different charge states. The calculated HR values and the related Debye-Waller factors guarantee that the Stone-Wales defects have a high potential of performing as a promising single-photon emitter.

Photoluminescence spectra of point defects in semiconductors: validation of first principles calculations

“…As for many properties of condensed systems, Density Functional Theory (DFT) has turned out to be a valuable tool to compute PL spectra, which are used to interpret experiments as well as to provide predictions of the fingerprints of specific defects in materials [7][8][9]. For example, first principles spectra based on DFT have been recently reported for nitrides, e.g., GaN [10,11], AlN [12], and hexagonal born nitride (h-BN) [13][14][15][16][17][18], diamond [19][20][21][22][23][24][25][26][27][28][29], silicon carbide (SiC) [30][31][32][33], and monolayers of transition metal dichalcogenides (TMDC) [34]. These studies have been performed with several useful computational approaches; however, a systematic assessment of the theoretical and numerical approximations adopted in PL calculations has not yet been conducted.…”