Bi基拓扑绝缘体纳米薄片的制备和输运性质的研究

Synthesis and transport properties of Bi-based topological insulator nanoplates

拓扑绝缘体表面态传输耗散少,有可能作为变电站中的电传输新材料.我们采用化学气相沉积法制备了Bi_2Te_3拓扑绝缘体纳米薄片,通过光学显微镜、原子力显微镜和扫描电镜表征,优化了制备参数进而获得Bi_2Te_3纳米薄片.采用光刻技术在Bi_2Te_3纳米薄片上制作金属电极,测量其输运性质,观察到了来自拓扑表面态的弱反局域化效应.运用传统的弱局域化理论得到表面态电子的退相干长度约为130 nm.

Topological insulators have the low transport consumption and could be possibly used as the novel electrical transport materials in transformer substation. Here,we use chemical vapor deposition method to synthesize Bi2Te3 topological insulator nanoplates. Through characterization of optical microscopy,atomic force microscopy and scanning electron microscopy,we optimize the synthetic parameters and further obtain the Bi2Te3 nanoplates. We employe photolithography technique to fabricate metallic electrodes based on nanoplates. We measure the transport properties and observe the weak antilocalization effect originated from the topological surface states. We apply the traditional weak localization theory and find that the coherence length of surface state electrons is approximately 130 nm.