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

作者：Wang Lin Lin^*; Huang Mianliang; Thimmaiah Srinivasa; Alam Aftab; Bud' ko Sergey L; Kaminski Adam; Lograsso Thomas A; Canfield Paul; Johnson Duane D

来源：Physical Review B, 2013, 87(12): 125303.

DOI：10.1103/PhysRevB.87.125303

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 %26gt; 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

• 出版日期2013-3-8