Native Defects in CdTe. Te Antisite and Cd Vacancy
(English)In: Journal of Physics: Condensed MatterArticle in journal (Other academic) Submitted
In this paper, we have studied Te antisites and Cd vacancies in CdTe by local density approximation (LDA) and hybrid functionals (HSE06) within density functional theory. We have shown that LDA, in spite of successful predictions of Te antisite geometries, fails in case of Cd vacancy. C3v and D2d symmetries of the VCd−1 and VCd0 defects were found only by HSE06, while LDA calculations resulted in Td symmetry for all of these defects. This mismatch consequently resulted in severe differences in the defects formation energies calculated by HSE06 and LDA. In contrast to LDA, our hybrid functional calculations agree well with experimental observations. For Te-rich conditions considering only native defects, our calculations predict CdTe to have a Fermi level of about 0.6 eV, because at that level the vacancy double acceptor and antisite double donor are compensated. We propose that the defect compensation may be the reason for high resistivities in undoped CdTe.
CdTe, Te antisite, Cd vacancy, Formation energies, HSE06
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-244955OAI: oai:DiVA.org:uu-244955DiVA: diva2:790123