Photoluminescence spectra of point defects in semiconductors - Validation of first-principles calculations
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2021-08-24 |
| Journal | Physical Review Materials |
| Authors | Yu Jin, Marco Govoni, Gary Wolfowicz, Sean E. Sullivan, F. Joseph Heremans |
| Institutions | University of Chicago, Argonne National Laboratory |
| Citations | 58 |
| Analysis | Full AI Review Included |
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View Original Abstract
Optically and magnetically active point defects in semiconductors are\ninteresting platforms for the development of solid-state quantum technologies.\nTheir optical properties are usually probed by measuring photoluminescence\nspectra, which provide information on excitation energies and on the\ninteraction of electrons with lattice vibrations. We present a combined\ncomputational and experimental study of photoluminescence spectra of defects in\ndiamond and SiC, aimed at assessing the validity of theoretical and numerical\napproximations used in first principles calculations, including the use of the\nFranck-Condon principle and the displaced harmonic oscillator approximation. We\nfocus on prototypical examples of solid-state qubits, the divacancy centers in\nSiC and the nitrogen-vacancy in diamond, and we report computed\nphotoluminescence spectra as a function of temperature that are in very good\nagreement with the measured ones. As expected we find that the use of hybrid\nfunctionals leads to more accurate results than semilocal functionals.\nInterestingly our calculations show that constrained density functional theory\n(CDFT) and time-dependent hybrid DFT perform equally well in describing the\nexcited state potential energy surface of triplet states; our findings indicate\nthat CDFT, a relatively cheap computational approach, is sufficiently accurate\nfor the calculations of photoluminescence spectra of the defects studied here.\nFinally, we find that only by correcting for finite-size effects and\nextrapolating to the dilute limit, one can obtain a good agreement between\ntheory and experiment. Our results provide a detailed validation protocol of\nfirst principles calculations of photoluminescence spectra, necessary both for\nthe interpretation of experiments and for robust predictions of the electronic\nproperties of point defects in semiconductors.\n