Chemical Interpretation of Charged Point Defects in Semiconductors: A Case Study of Mg₂Si

Abstract

The electronic structures of charged point defects influence electrical and optical properties of semiconductors. Understanding the orbital interactions responsible for the electronic structures of defects therefore promotes a chemical intuition for defect‐driven mechanisms in semiconductors. In this tutorial, we discuss a molecular orbital theory‐based framework for understanding defect‐induced electronic states based on local chemical interactions between the defect and the atoms surrounding the defect site. By using Mg2Si as a case study, we show how both the chemical interactions and molecular orbitals (i. e., wave functions) responsible for the charge state(s) of a defect can be understood from the bonding symmetry of the defect site. We anticipate that a chemistry‐based perspective of charged defects will enrich defect engineering efforts for electronic and optical materials.

VTAnDeM: A Python Toolkit for Simultaneously Visualizing Phase Stability, Defect Energetics, and Carrier Concentrations of Materials

“…Defect formation energy diagrams convey how the formation energy ∆E D,q of an isolated point defect D with charge state q varies with the Fermi energy. 48 Within the supercell approach, [49][50][51] the defect formation energy is calculated as…”