Abstract
We use hybrid functionals and restricted self-consistent , state-of-the-art theoretical approaches for quasiparticle band structures, to study the electronic states of delafossite , the first -type and bipolar transparent conductive oxides. We show that a self-consistent approximation gives remarkably wider band gaps than all the other approaches used so far. Accounting for polaronic effects in the scheme we recover a very nice agreement with experiments. Furthermore, the modifications with respect to the Kohn-Sham bands are strongly dependent, which makes questionable the common practice of using a scissor operator. Finally, our results support the view that the low energy structures found in optical experiments, and initially attributed to an indirect transition, are due to intrinsic defects in the samples.
- Received 1 October 2009
DOI:https://doi.org/10.1103/PhysRevLett.104.136401
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