Identifying Native Point Defects in the Topological Insulator BiTe.

We successfully identified native point defects that occur in BiTe crystals by combining high-resolution bias-dependent scanning tunneling microscopy and density functional theory based calculations. As-grown BiTe crystals contain vacancies, antisites, and interstitial defects that may result in bulk conductivity and therefore may change the insulating bulk character. Here, we demonstrate the interplay between the growth conditions and the density of different types of native near-surface defects.