Topological Material of Vertical Standing Sb2Te3 Nanoflakes Synthesis
Y.Q. Chang1,2*, W.H. Tsai1, C.H. Chien1,3, Y.Y. Chou1,2, Y.Y. Chen1,4
1Institute of Physics, Academia Sinica, Nankang, Taiwan
2Department of Physics, Soochow University, Taipei, Taiwan
3Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan
4Graduate Institute of Applied Physics, National Chengchi University, Taipei, Taiwan
* presenting author:Yu-Qian Chang,
We report a special method to fabricate the vertical and planar single-crystalline antimony telluride nanoflakes (NFs) on SiO2 substrate. The growth mechanism of thin and standing single-crystalline NF is a key point to transfer a thin NF on the measurement chip. NFs were grown using a chemical vapor transport (CVT) method. The chemical vapor concentration is important parameter in this process. In the larger quartz tube, we put few smaller ones into it to change the original space which is in order to adjust the vapor concentration. Compare with the one without the smaller quartz tubes inside, the vapor from antimony telluride target will be condensed on SiO2 substrate readily. This method also causes the standing and thinner NFs on the SiO2 substrate finally. The scanning electron microscope (SEM) and atomic force microscope (AFM) will be utilized to observe the morphology and thickness of NFs, respectively. We transferred a single suitable NF on the measurement chip by using mechanical micromanipulator. Differ from the traditional transfer methods, this fabrication process will be quick, efficient and clean. To sum up, we have successfully tuned the well condition of growth mechanism, and do the measurements to study their physical properties.

Keywords: chemical vapor transport, nanoflake, Sb2Te3