Critical evaluation of the LDA + U approach for band gap corrections in point defect calculations: The oxygen vacancy in ZnO case study

Abstract

AbstractThe LDA + U approach can be used essentially as a shift potential to open up the band gap of a semiconductor. This approach was previously applied to the oxygen vacancy in ZnO by Paudel and Lambrecht (PL) [Phys. Rev. B 77, 205202 (2008)]. Here, we review the results of that approach and introduce additional refinements of the LDA + U model. Good agreement is obtained with recent hybrid functional calculations on the position of the ${\varepsilon} (2 + /0)$ transition state. A comparison of various approaches on the oxygen vacancy in ZnO is provided. The relevance of the one‐electron levels to the experiments is discussed.