Scientists find better way to model defects in diamond and other materials
Researchers have developed a cleaner computational method for studying charged defects in semiconductors and insulators like diamond, eliminating artificial approximations that have plagued the field. The advance could accelerate materials discovery for quantum computing, power electronics, and other high-value applications where defect behavior directly impacts device performance.
Originaltitel: Neutral supercells for charged impurities by explicit acceptor/donor compensation - Defects in diamond
<p>When investigating charged defects in semiconductors or insulators, the traditional method to render them charged is by adding/removing electrons to/from the supercell. However, this method can be problematic due to the necessity to include an artificial jellium counter-charge. Herein, we investigate an alternative approach to charging - using explicit compensating donors/acceptors, in the form of substitutional atoms with suitable valence. This method yields pairs of charged defects in neutral supercells, thereby eliminating the need for jellium altogether. We test the method for a collection of model systems consisting of charge-compensated point defects in diamond (NV/SiV-centers, substitutional nitrogen/phosphorous/oxygen/sulfur donors, and substitutional boron/beryllium acceptors). We report the resulting charges, local geometries, spin densities, Kohn-Sham energy levels, and electronic transition energies for selected defect pairs and compare them with those for the individual defects in charged supercells. We find that charging by explicit donors/acceptors works well if properly designed but interpretation of the results can be challenging. We advocate for the cautious use of this approach to complement traditional charge correction schemes and to analyze the charge-compensation mechanisms occurring in actuality.</p>