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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 15: Postersession KFM

KFM 15.28: Poster

Donnerstag, 19. März 2020, 16:00–18:30, P2/1OG

Defect engineering in a single TiS3: A first-principles study — •Guy Moise Dongho-Nguimdo, Emmanuel l. Igumbor, Raji A. Tunde, Evans M. Benecha, and Enrico B. Lombardi — College of Science, Engineering and Technology, University of South Africa, P.O. Box 392, UNISA 0003 Pretoria, South Africa.

Contrary to other transition metal chalcogenides (TMC), TiS₃ has not received attention despite its relative easy exfoliation, and high carrier mobility. In this work, we used DFT investigate the stability, the structural and the electronic properties of vacancy and antisite defects in the transition metal trichalcogenides TiS3. It is found that the formation energy is strongly dependent on which of the symmetrically inequivalent sites the defect is located. In contrast to the dichalcogenide analogs, the energy required to create a sulfur divacancy under Ti-rich conditions are lower than that of the single vacancy independently of the location of the sulfur vacancy. The negative binding energy of the double vacancies is an indication that they will likely depose into the single sulfur defects. Based on both the binding and the formation energy, we also demonstrate that the Ti-rich is the ideal growth condition for the formation of the vacancy complexes. The presence of intermediate states in the bandgap of most of the defects considerably affects the electronic properties of the pristine, with the possibility of n-type and p-type conductivity. With the exception of V_S¹, V_TiS³, V_Ti4S¹, V_Ti4S¹4S³, S_Ti and Ti_S³S_Ti, where there is no trace of magnetism as in the pristine system; all other defects acquired some magnetic moment.