Cl-doping of Te-rich CdTe: Complex formation, self-compensation and self-purification from first principles
2015 (English)In: AIP Advances, ISSN 2158-3226, E-ISSN 2158-3226, Vol. 5, no 8, 087101Article in journal (Refereed) Published
The coexistence in Te-rich CdTe of substitutional Cl-dopants, Cl-Te, which act as donors, and Cd vacancies, V-Cd(-1), which act as electron traps, was studied from first principles utilising the HSE06 hybrid functional. We find ClTe to preferably bind to V-Cd(-1) and to form an acceptor complex, (Cl-Te-V-Cd)(-1).The complex has a (0,-1) charge transfer level close to the valence band and shows no trap state (deep level) in the band gap. During the complex formation, the defect state of V-Cd-(1) is annihilated and leaves the Cl-doped CdTe bandgap without any trap states (self-purification). We calculate Cl-doped CdTe to be semi-insulating with a Fermi energy close to midgap. We calculate the formation energy of the complex to be sufficiently low to allow for spontanous defect formation upon Cl-doping (self-compensation). In addition, we quantitatively analyse the geometries, DOS, binding energies and formation energies of the (Cl-Te-V-Cd) complexes.
Place, publisher, year, edition, pages
2015. Vol. 5, no 8, 087101
IdentifiersURN: urn:nbn:se:uu:diva-263458DOI: 10.1063/1.4928189ISI: 000360655900010OAI: oai:DiVA.org:uu-263458DiVA: diva2:859203