Color Centers in Semiconductors for Quantum Applications : A High-Throughput Search of Point Defects in SiC

Abstract

Defect hull by Joel DavidssonA computer graphics image generated from the combined data from Figure 6.4 and Figure 6.5. Each sphere represents a calculated point defect. The x and y coordinates are the stoichiometry, and the z coordinate is the formation energy with a Fermi energy in the middle of the band gap. The colors represent the zero phonon lines (ZPLs) normalized by the PBE band gap value and color mapped using the Viridis color scheme. The brightness around each sphere represents the transition dipole moment (TDM) squared.

Exhaustive characterization of Si vacancy complex in 4H-SiC

“…To narrow down the number of possible defects that fit the observed experimental data, we turn to the high-throughput data [31][32][33] produced by ADAQ [34] that is implemented with the high-throughput toolkit httk [35]. ADAQ is a collection of automatic workflows designed to speed up the search for point defects.…”

“…Previously, ADAQ was employed on 4H-SiC and screened 8355 single and double intrinsic defects in 4H-SiC [32]. The detailed report on the results collected in a database will be presented elsewhere [31,33].…”

“…These settings roughly correspond to point defect clusters with second nearest neighbors. To keep track of the most stable defects, the concept of the defect hull is introduced [32] which consists of the point defects with the lowest formation energy for a given stoichiometry. The defect hull is analogous to the convex hull of stability used to discuss the thermodynamical stability of bulk materials.…”

“…Sec. II outlines how we search for point defects that explain the observations related to the silicon vacancy in data produced in high-throughput calculations [31][32][33] with Automatic Defect Analysis and Qualification (ADAQ) [34] . This search shows that silicon vacancies modified by carbon antisites are the only candidates among thousands of considered point defects.…”

Ab Initio Modeling of Magnetic Materials in the High-Temperature Paramagnetic Phase

“…These defects affect the optical properties of the system, similarly to what happens in colored diamonds. An example of a current research field related to this effect involves defects in silicon carbide [13], which are investigated as, for example, emitters of single photons.…”