Tuning the Fermi level (E_F) in Bi₂Te₃ topological-insulator (TI) films is demonstrated on controlling the temperature of growth with molecular-beam epitaxy (MBE). Angle-resolved photoemission spectra (ARPES) reveal that E_F of Bi₂Te₃ thin films shifts systematically with the growth temperature (T_g). The key role that a Bi-on-Te(1) (Bi_Te1) antisite defect plays in the electronic structure is identified through extended X-ray-absorption fine-structure (EXAFS) spectra at the Bi L₃-edge. Calculations of electronic structure support the results of fitting the EXAFS, indicating that the variation of E_F is due to the formation and suppression of Bi_Te1 that is tunable with the growth temperature. Our findings provide not only insight into the correlation between the defect structure and electronic properties but also a simple route to control the intrinsic topological surface states, which could be useful for applications in TI-based advanced electronic and spintronic devices.

中文翻译：

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反位缺陷对Bi ₂ Te ₃拓扑绝缘体 电子结构的影响

通过控制分子束外延（MBE）的生长温度，证明了在Bi ₂ Te ₃拓扑绝缘体（TI）薄膜中调节费米能级（E _F）。角度分辨光发射光谱（ARPES）表明，Bi ₂ Te ₃薄膜的E _F随着生长温度（T _g）而系统地移动。通过在Bi L ₃处扩展的X射线吸收精细结构（EXAFS）光谱，确定了Bi-on-Te（1）（Bi _Te1）反位缺陷在电子结构中的关键作用。-边缘。电子结构的计算支持拟合EXAFS的结果，表明E _F的变化是由于Bi _Te1的形成和抑制所致，Bi _Te1随生长温度可调。我们的发现不仅提供了对缺陷结构与电子特性之间关系的深入了解，而且还提供了一种控制固有拓扑表面状态的简单途径，这对于在基于TI的先进电子和自旋电子器件中的应用可能是有用的。