Controlling bulk conductivity in topological insulators: key role of anti-site defects.

Intrinsic topological insulators are realized by alloying Bi(2)Te(3) with Bi(2)Se(3). Angle-resolved photoemission and bulk transport measurements reveal that the Fermi level is readily tuned into the bulk bandgap. First-principles calculations of the native defect landscape highlight the key role of anti-site defects for achieving this, and predict optimal growth conditions to realize maximally resistive topological insulators.