Deposition of topological insulator Sb2Te3 films by an MOCVD process
Deposition of topological insulator Sb2Te3 films by an MOCVD process
复制标题
DOI：
10.1039/c4ta00707g
复制
发表时间：
2014-01-01
影响因子：
11.9
通讯作者：
Schulz, Stephan
中科院分区：
文献类型：
--
作者：
Bendt, Georg;Zastrow, Sebastian;Schulz, Stephan
使用 i-Pr3Sb 和 Et2Te2，通过 MOCVD 工艺在 Al2O3(0001) 衬底上于 400 摄氏度下生长层状 Sb2Te3 薄膜，并通过 SEM、AFM、XRD、EDX 和俄歇能谱进行表征。在 4 至 400 K 范围内测量了薄层电阻率，显示出随温度升高单调增加。通过角分辨光电发射探测的价带结构显示了块体价带的详细色散和质量不低于优化块体单晶的拓扑表面状态。表面态色散使狄拉克点比费米能级高出大约 30 meV，从而导致空穴掺杂并在费米能级处出现体价态。
Layered Sb2Te3 films were grown by a MOCVD process on Al2O3(0001) substrates at 400 degrees C by use of i-Pr3Sb and Et2Te2 and characterized by SEM, AFM, XRD, EDX and Auger spectroscopy. The electrical sheet resistivity was measured in the range of 4 to 400 K, showing a monotonic increase with increasing temperature. The valence band structure probed by angle-resolved photoemission shows the detailed dispersions of the bulk valence band and the topological surface state of a quality no less than for optimized bulk single crystals. The surface state dispersion gives a Dirac point roughly 30 meV above the Fermi level leading to hole doping and the presence of bulk valence states at the Fermi energy.