二硒化?閘極場效元件弱局域化現象研究

Abstract

本論文針對化學氣相沉積的少層二硒化錫在石墨烯上的薄片材料進行磁電阻效應的研究，並觀察到吻合Hikami-Larkin-Nagaoka模型的弱局域效應，研究中發現可以透過溫度及閘極電壓控制相位相干長度，藉由調控的機制，在溫度為 1 K 閘極電壓為 -20 V 時相位相干長度約為 540 nm 。 研究中也探討二硒化錫類似於電晶體的電傳輸特性，其中載子遷移率和載子密度高度依賴於溫度和柵極電壓。根據上述結果，我們提出了一些方法來改善二硒化錫場效元件的開關比，這讓未來針對二維材料奈米場效元件的研究和開發有著很大的優勢。

We have conducted an investigation into the magneto-transport properties of chemical vapor deposition few-layer SnSe2 flake on monolayer graphene. The observed weak localization magnetoresistance agrees well with the Hikami-Larkin-Nagaoka model, and the phase coherence length can be tuned by controlling the temperature and gate voltage. We find that the phase coherence length is around 540 nm when a voltage of -20 V is applied on the back gate at 1 K. We also show the field-effect-transistor-like behavior of SnSe2, in which the mobility and carrier density are highly dependent on temperature and gate voltage. According to the aforementioned results, we propose some method to increase the on-off ratio of a SnSe2-based device, a great advantage for future two-dimensional material-based nano-switch device.