二硒化錸表面鍍鎳原子致形貌及電性變化

Abstract

二硒化錸(ReSe2)是過渡金屬二硫族化物(TMDs)的一員，先前許多的研究皆表示TMDs材料如何處理皆會有產生原子級缺陷，近年來更是對缺陷工程(Defect Engineering)感興趣，想在樣品上製造出新的缺陷，以了解會有哪些物理特性。本實驗室利用超高真空系統使研究的樣品表面可以有一乾淨的環境來研究，並使用掃描式穿隧顯微鏡(Scanning tunneling microscope, STM)來進行原子級的表面及缺陷測量，和使用掃描穿隧能譜 (Scanning tunneling spectroscopy, STS)進行樣品的電性量測及分析。本研究採用機械剝離法製備二硒化錸（ReSe₂）樣品，並結合電子束蒸鍍技術進行鎳（Ni）原子的沉積。透過表面形貌觀察與晶格結構分析，系統性探討鎳原子附著於ReSe₂表面後之形貌變化與分布特性。同時，進一步量測其表面態電子特性，以評估鎳原子吸附對ReSe₂能帶結構之影響，進而深入了解其潛在的材料調控機制與應用可能性。在對鎳蒸鍍後的二硒化錸（ReSe₂）表面進行觀察與分析後發現，鎳原子在ReSe₂表面上可穩定形成具有2.2±0.4 nm的原子團簇。此外，鎳的存在有助於抑制外來雜質於表面的附著，顯示其對表面清潔度具有正面影響。進一步將鍍鎳與鍍鐵之ReSe₂樣品進行比較分析，結果顯示，相較於鍍鐵樣品中觀察到的憶阻器效應（memristor effect），鍍鎳樣品中並未出現類似的現象，顯示不同過渡金屬元素對ReSe₂表面電性行為具有顯著差異。Rhenium diselenide (ReSe2), a member of the transition metal dichalcogenides (TMDs), is known to exhibit atomic-scale defects regardless of processing methods. In recent years, interest has shifted toward defect engineering, aiming to intentionally create defects to study their impact on physical properties.In this work, we used an ultra-high vacuum (UHV) system to maintain a clean surface environment, and employed scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) to investigate the atomic-scale structure and electronic properties of ReSe2.ReSe2 samples were prepared by mechanical exfoliation, followed by Ni deposition electron beam evaporation. Surface morphology and lattice structure analyses revealed that Ni atoms form stable clusters averaging 2.2 ± 0.4 nm in size. Ni adsorption also reduced contamination, improving surface cleanliness.Comparative studies showed that, unlike Fe-deposited samples which exhibited memristor-like behavior, Ni-deposited samples did not. These findings highlight how different transition metals can significantly influence the electronic behavior of ReSe2 surfaces.