Native defects in tetradymite Bi-2(TexSe3-x) topological insulators

TitleNative defects in tetradymite Bi-2(TexSe3-x) topological insulators
Publication TypeJournal Article
Year of Publication2013
AuthorsWang LL, Huang ML, Thimmaiah S, Alam A, Bud'ko SL, Kaminski A, Lograsso TA, Canfield P, Johnson DD
Journal TitlePhysical Review B
Volume87
Pages125303
Date Published03
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000316103800005
Keywordsbi2te3, ELECTRON-GAS, energy, quantum oscillations, semiconductors, surface-states
Abstract

Formation energies of native defects in Bi-2(TexSe3-x), with comparison to ideal Bi2Te2S, are calculated in density-functional theory to assess transport properties. Bi2Se3 is found to be n type for both Bi- and Se-rich growth conditions, while Bi2Te3 changes from n to p type going from Te- to Bi-rich conditions, as observed. Bi2Te2Se and Bi2Te2S are generally n type, explaining observed heavily doped n-type behavior in most samples. A (0/-) transition level at 16 meV above valence-band maximum for Bi on Te antisites in Bi2Te2Se is related to the observed thermally active transport gap causing a p-to-n transition at low temperature. Bi-2(TexSe3-x) with x > 2 are predicted to have high bulk resistivity due to effective carrier compensation when approaching the n-to-p crossover. Predicted behaviors are confirmed from characterization of our grown single crystals. DOI: 10.1103/PhysRevB.87.125303

URL<Go to ISI>://WOS:000316103800005
DOI10.1103/PhysRevB.87.125303