拉曼光谱
外延
分子束外延
材料科学
拓扑绝缘体
电介质
铋
基质(水族馆)
分析化学(期刊)
超晶格
光学
凝聚态物理
化学
纳米技术
光电子学
物理
冶金
地质学
海洋学
色谱法
图层(电子)
作者
Tomohiro Kondo,Takamu Nozaki,Ryuya Kotabe,Yoshikazu Terai
标识
DOI:10.35848/1347-4065/acaab3
摘要
Abstract Bismuth selenide (Bi 2 Se 3 ) epitaxial films were grown at different substrate temperatures ( T s ) by molecular beam epitaxy. In the optimization of T s , a Bi 2 Se 3 film with the smallest root mean square roughness (Rq) and the lowest electron density was grown at T s = 120 °C. In the optimized growth condition, Bi 2 Se 3 epitaxial films with 3−85 quintuple layers (QL: 1 QL ≈ 1 nm) were grown. In unpolarized Raman spectra, the positions of A 1 1g and E 2 g -modes shifted to the low wavenumbers at film thickness below 10 QL. The polarized Raman spectra showed that the depolarization ratio ρ also changed with film thickness. The change in ρ was more significant than the change in the position shift. This indicates that the measurement of ρ is an effective method to evaluate the thickness of Bi 2 Se 3 ultrathin films.
科研通智能强力驱动
Strongly Powered by AbleSci AI