原子级锡基薄膜及其异质结构的制备与物性研究

The preparation and properties analysis of two-dimensional (2D) tin materials have become an important issue in the field of condensed matter physics since the novel quantum effects of stanene were predicted in 2013. This project is intended to study the epitaxial growth and physical properties of the atomic-scale Tin films and their heterostructures by combining advanced experimental techniques and theoretical calculations. Firstly, we will seek the optimal substrate materials and preparation conditions for stanene based on the theoretical models. The high quality 2D tin thin films are expected to be prepared by molecular beam epitaxy under ultrahigh vacuum conditions. Their electronic structures will be regulated by doping or surface modification, which would result in new Sn-related thin films. Furthermore, magnetic materials will be involved to fabricate the stanene-based heterostructures. By utilizing scanning tunneling microscopy and other modern characterization techniques combined with the first-principles calculation, these 2D systems will be investigated in detail, including their surface/interface structures and physical properties, to understand the novel quantum phenomena and mechanism at the electronic level. The results obtained will be beneficial for the development of the Sn-related 2D materials with novel physical performance.

自2013年二维锡烯材料的新奇量子效应被理论预言以来，其实验制备和物性分析成为凝聚态物理领域的一个重要研究课题。本项目拟结合先进的实验技术和理论计算方法，研究锡烯等原子级锡基薄膜及其异质结构的外延生长和结构物性。我们将基于理论模型设计进行实验探索，寻求合适的生长衬底和制备工艺条件，采用超高真空分子束外延方法，从原子尺度上精确控制材料的生长，实现高质量二维锡烯薄膜的可控制备。通过表面修饰或掺杂，调控体系的电子结构以获得新型的锡基薄膜，并进一步结合磁性材料构建异质结构。利用扫描隧道显微镜/谱等高分辨测量技术的原位表征，结合第一性原理计算，研究原子级锡基薄膜材料体系的表面/界面结构及物理特性，从电子层面上理解其新奇量子现象的内在机理，探索其电子结构和物理性能的调控方法，为发展新型锡基二维材料提供科学数据。

本项目研究工作主要围绕原子级锡基薄膜及其异质结构开展，结合理论模拟和实验探索，对二维锡基材料的制备控制、结构表征和物性分析等方面进行了研究。理论方面，采用第一性原理计算方法，对锡烯等二维材料的电子结构和物理特性进行预测分析，提出具有新奇量子现象的材料体系及其可能的性能调控方法。实验方面，采用超高真空分子束外延方法，从原子尺度上精确控制材料的生长，结合扫描隧道显微镜等原位表征手段，研究锡等材料在不同衬底上的生长规律和结构性质。通过生长条件的探索和优化，制备得到了原子级厚度的薄膜，形成了一套较为完整的实验制备方案。采用改进的化学气相沉积方法，制备得到大尺寸高质量的锡基硫族化合物二维单晶和薄膜及其异质结构。利用扫描电镜、原子力显微镜和拉曼光谱等表征技术，观测其表面/界面结构，结合理论模拟，分析体系结构特性和形成机理，探索异质结构体系的新奇物性和潜在应用。此外，在原计划研究内容的基础上，我们拓展研究了几种新型二维材料体系的构建和结构特性，取得了一系列有意义的研究成果。