Step-Flow Growth of Bi2Te3 Nanobelts

详细信息    查看全文

• 作者：Piet Schönherr ; Thomas Tilbury ; Haobei Wang ; Amir A. Haghighirad ; Vesna Srot ; Peter A. van Aken ; Thorsten Hesjedal
• 刊名：Crystal Growth & Design
• 出版年：2016
• 出版时间：December 7, 2016
• 年：2016
• 卷：16
• 期：12
• 页码：6961-6966
• 全文大小：441K
• ISSN：1528-7505

文摘

Understanding the growth mechanism of nanostructures is key to tailoring their properties. Many compounds form nanowires following the vapor–liquid–solid (VLS) growth mechanism, and the growth of Bi₂Te₃ nanobelts was also explained following the VLS route. Here, we present another growth mechanism of Bi₂Te₃ nano- and submicron belts and ribbons. The samples were grown by physical vapor transport from Bi₂Te₃ precursors using TiO₂ nanoparticles as a catalyst and analyzed by scanning electron microscopy and scanning transmission electron microscopy. The growth starts from a Te-rich cluster and proceeds via a thin, tip-catalyzed primary layer growing in the [110] direction. The primary layer serves as a support for subsequent step-flow growth. The precursor predominantly absorbs on the substrate and reaches the belt by migration from the base to the tip. Terrace edges pose energy barriers that enhance the growth rate of secondary layers compared to the primary layer. Broadening of the sidewalls is commonly observed and leads to triangular voids that can even result in a branching of the growing belts. Step-flow growth of Bi₂Te₃ submicron belts is different from the spiral-like growth mode of Bi₂Te₃ thin films and an important step toward the growth of layered topological insulator nanostructures.