| 摘要: | 拓樸絕緣體在十幾年來不斷受到重視，因為他是一種新型的量子材料，本身具有獨特效應，像是時間反轉對稱性和自旋-軌道耦合效應，使其3維表面態以及2維邊緣態受到保護，產生獨特特的電學特性；利用上述效應與特性，可以在許多方面得到應用，除這幾年已經開始商業化生產的量子電腦上的應用外，還有在光偵測器、場效電晶體、自旋電子元件、表面電將共振生物感測元件、超導元件。
本實驗利用鉍(Bi)粉末與碲(Te)粉末做為原料，在水平式爐管設備中，透過蒸鍍技術合成Bi2Te3，並添加碳(C)粉末做為氧化犧牲材料，吸收製程中多餘的氧(O)；純鉍粉末與純碲粉末，會隨時間與大氣中的氧氣反應，生成氧化物Bi2O3與TeO2，如果製程在不添加C的情況下，TeO2的氧原子將釋放，導致原料Bi粉末氧化成Bi2O3，降低整體Bi2Te3產量。
本次實驗固定Bi粉末重量比例為1、Te粉末重量比例為1，與碳粉末重量比例為0、0.05、0.1、1分別比較，0為不添加，0.005為微量添加，0.01為等體積添加，0.1為等重量添加；最後將試片透過X光繞射儀，對其晶體結構進行分析。
由最終結果得到證實，透過添加0.1g的C進行過量參雜，可以有效保護原料不被氧化，提升Bi2Te3品質。
Nearly ten years, topological insulator has been highly valued. Because it is a new type of quantum material with unique effects, like time reversal symmetry and spin–orbit interaction effect, so that 3D surface state and 2D edge states have been protected to produce unique electrical characteristics. Using the above-mentioned functions and characteristics, it can be applied in many ways. In addition to the applications in the commercial production of quantum computers, there are also photodetector, field-effect transistor, spintronic-logic devices, surface plasmon resonance biosensor and superconducting device.
This experiment uses bismuth (Bi) powder and tellurium (Te) powder as raw materials. The Bi2Te3 is synthesized through physical vapor deposition In the conventional thermal annealing. At the same time, process adds carbon (C) powder to treat as oxidation sacrificial material to absorb excess oxygen (O). The pure Bi powder and pure Te powder will react with O2 in the atmosphere over time to form oxides Bi2O3 and TeO2. If the process does not add C, the oxygen atoms of TeO2 will be released, resulting in raw materials Bi powder is oxidized to Bi2O3, which reduces the overall Bi2Te3 output.
In this experiment, the weight ratio of Bi powder is fixed to 1, the weight ratio of Te powder is 1, compared with the weight ratio of C powder to 0, 0.05, 0.1, 1, respectively, 0 means no addition, 0.005 is a trace addition, and 0.01 is an equal volume addition. 0.1 is an equal weight addition; finally, the test piece is passed through an X-ray diffractometer to analyze its crystal structure.
It is confirmed from the final result that adding 0.1g of C for excessive mixing can effectively protect the raw materials from Oxidation, that do not be oxidized and improve the quality of Bi2Te3. |
