二硒化錸機械剝離前後及氧致缺陷變化
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2022
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二硒化錸 (ReSe2) 層狀結構的半導體屬於過渡金屬二硫族化物 (TMD) 材料。層狀材料 (二維材料) 發展快速，在半導體產業上有廣泛的應用。而我們使用超高真空環境下，進行STM 與 STS 測量，來了解ReSe2表面物理特性。利用機械剝離方法 (Fresh) 觀測ReSe2前、後、曝氧表面，發現表面上有相關的變化。形貌上我們可以得知主要由亮暗點所構成，以往ReS2、MoS2 、MoSe2同屬二維材料的樣品中亦可觀察到亮暗點的變化，而ReSe2中更可以發現曝氧時顯著的差異於表面上呈現，我們可透過比對其他二維材料樣品後發現，ReSe2樣品於表面上吸附氧的能力有所不同。此次實驗在室溫下STM表面掃圖也較為清晰，更於小尺度時有清晰的原子結構表現。我們接著使用掃描穿隧能譜 (STS) 進行電性上的分析，較為明顯的比較於曝氧後與曝大氣後有相關，這也是我們曝氧的目的，進而佐證大氣中影響的主要角色為何?實驗的主體為形貌分析與電性分析，主要以分段放氧來分析ReSe2樣品，比較後可發現氧氣在ReSe2表面上有更強的吸附力，也是能隙調控的重要條件之一。
Rhenium diselenide (ReSe2) layered semiconductors are transition metal dichalcogenide (TMD) materials. Layered materials (two-dimensional materials) are developing rapidly and have a wide range of applications in the semiconductor . We use the ultra-high vacuum environment to perform STM and STS measurements in order to understand the physical properties of the ReSe2 surface.The mechanical exfoliation method (Fresh) was used to observe the surface of ReSe2 before, after, and oxygen exposure, and it was found that there were relevant changes on the surface. From the morphology, we can know that it is mainly composed of bright and dark points. In the past, ReS2、MoS2 and MoSe2 (two-dimensional materials) . The change of bright and dark spots can also be observed. In ReSe2, a significant difference can be found when oxygen exposed . On the surface, we can find that the ability of ReSe2 samples to adsorb oxygen on the surface is different by comparing with other two-dimensional material samples . In this experiment, the STM at room temperature is also clearer, and the atomic structure is more clearly expressed at small scales.And then, we also used scanning tunneling spectroscopy (STS) to analyze the electrical properties, which is more obviously related to the air exposure (After Fresh) and after oxygen exposure.The main subject of the experiment is morphology analysis and electrical analysis. Different from previous experiments, ReSe2 samples are mainly analyzed by staged observation. After comparison, it can be found that oxygen has a stronger adsorption on the surface of ReSe2. One of the important conditions for adjusting the energy gap.
Rhenium diselenide (ReSe2) layered semiconductors are transition metal dichalcogenide (TMD) materials. Layered materials (two-dimensional materials) are developing rapidly and have a wide range of applications in the semiconductor . We use the ultra-high vacuum environment to perform STM and STS measurements in order to understand the physical properties of the ReSe2 surface.The mechanical exfoliation method (Fresh) was used to observe the surface of ReSe2 before, after, and oxygen exposure, and it was found that there were relevant changes on the surface. From the morphology, we can know that it is mainly composed of bright and dark points. In the past, ReS2、MoS2 and MoSe2 (two-dimensional materials) . The change of bright and dark spots can also be observed. In ReSe2, a significant difference can be found when oxygen exposed . On the surface, we can find that the ability of ReSe2 samples to adsorb oxygen on the surface is different by comparing with other two-dimensional material samples . In this experiment, the STM at room temperature is also clearer, and the atomic structure is more clearly expressed at small scales.And then, we also used scanning tunneling spectroscopy (STS) to analyze the electrical properties, which is more obviously related to the air exposure (After Fresh) and after oxygen exposure.The main subject of the experiment is morphology analysis and electrical analysis. Different from previous experiments, ReSe2 samples are mainly analyzed by staged observation. After comparison, it can be found that oxygen has a stronger adsorption on the surface of ReSe2. One of the important conditions for adjusting the energy gap.
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掃描穿隧式顯微鏡, 二硒化錸, 曝氧氣, STM, ReSe2, Exposed oxygen