| 研究実績の概要 |
We have carried out electronic structure calculations of various defects in GaN and Ga2O3. For GaN, we have focused on the deep Mn and Fe impurities, as well as shallow acceptor Mg. For Ga2O3, in addition to beta phase, we also investigate epsilon and kappa phases, and focus on Cr and Co impurities.
1. We have observed various polaronic states for Mg impurities in GaN, and investigate in detail their sensitivity to strain. In addition to thermodynamic stabilities and thermodynamic transitions, also optical lines are calculated for comparison with experiment. Our calculation clarifies various optical transitions that have been heavily debated in literature. We are in the process of publishing these results.
2. For Ga2O3, we have discovered carrier-mediated ferromagnetism in Cr-doped beta-Ga2O3, as well as described the optical properties of Co-doped epsilon and kappa phases of Ga2O3. Both works are published in peer-reviewed journals.
3. Our review on piezomagnetism in magnetic semiconductors is still under preparation. In addition, a review on first principles methods for defect calculations of semiconductors was published as a book chapter in "Characterization and Control of Defects in Semiconductors" (Ed. F. Tuomisto, IET, United Kingdom 2019).
4. We have expanded this work to the investigation of polaron states in cunprate superconductors. Publication under preparation.
|
