Short-range atomic ordering in nonequilibrium silicon-germanium-tin semiconductors
Short-range atomic ordering in nonequilibrium silicon-germanium-tin semiconductors
复制标题
非平衡硅-锗-锡半导体中的短程原子有序性
DOI：
10.1103/physrevb.95.161402
复制
发表时间：
2017
影响因子：
3.7
通讯作者：
O. Moutanabbir
中科院分区：
文献类型：
--
作者：
S. Mukherjee;N. Kodali;D. Isheim;S. Wirths;J. Hartmann;D. Buca;D. Seidman;O. Moutanabbir
对单晶合金原子顺序的精确认识是理解和预测其物理性质的基础。从这个角度来看，我们利用激光辅助原子探针断层扫描研究了非平衡外延富锡族iv SiGeSn三元半导体中原子的三维分布。采用不同的原子探针统计分析工具，包括频率分布分析、部分径向分布函数和最近邻分析，以评估和比较这三种元素在理想固溶体中的空间分布。这种原子水平的分析提供了明确的证据，表明锡和硅之间意外的排斥相互作用导致硅原子偏离理论随机分布。这种偏离理想固溶体的情况得到第一性原理计算的支持，并归因于系统在逐层生长过程中降低混合焓的趋势。
The precise knowledge of the atomic order in monocrystalline alloys is fundamental to understand and predict their physical properties. With this perspective, we utilized laser-assisted atom probe tomography to investigate the three-dimensional distribution of atoms in nonequilibrium epitaxial Sn-rich group-IV SiGeSn ternary semiconductors. Different atom probe statistical analysis tools including frequency distribution analysis, partial radial distribution functions, and nearest-neighbor analysis were employed in order to evaluate and compare the behavior of the three elements to their spatial distributions in an ideal solid solution. This atomistic-level analysis provided clear evidence of an unexpected repulsive interaction between Sn and Si leading to the deviation of Si atoms from the theoretical random distribution. This departure from an ideal solid solution is supported by first-principles calculations and attributed to the tendency of the system to reduce its mixing enthalpy throughout the layer-by-layer growth process.