论文标题
识别在Al（111）表面生长的德国烯的合金结构
Identifying the Alloy Structures of Germanene Grown on Al(111) Surface
论文作者
论文摘要
尽管在许多底物上宣称德国烯的生长，但确切的晶体结构仍然存在争议。在这里，我们通过结合密度功能理论（DFT）和全局优化算法来系统地探索GE沉积在AL（111）表面上形成的可能结构。我们表明，通过高级随机相近似（RPA）计算，Al（111）上德国烯的形成在阳性形成能上在能量上不利。两个实验阶段通过结合启动进化模拟，RPA计算，以及可从扫描隧道显微镜（STM）和低启动Electron（led-Electry difaction（Leed difactraction con）结合，将两个实验阶段鉴定为蜂窝合金AL3GE3/AL（111）（R7XR7）和AL3GE4/AL（111）（3x3）（3x3）（3x3）。 AL3GE4/AL（111）（3x3）是一个有趣的结构，在基板中具有空缺，它说明了实验STM图像中的深色三叶草模式。我们的结果阐明了GE/AL（111）系统的结构性争议，表明德国烯的制造可能仍然具有挑战性。
While the growth of germanene has been claimed on many substrates, the exact crystal structures remain controversial. Here, we systematically explore the possible structures formed by Ge deposition onto Al(111) surface by combining density-functional theory (DFT) and global optimization algorithm. We show that, by high-level random-phase approximation (RPA) calculations, the formation of germanene on Al(111) is energetically unfavorable with positive formation energy. The two experimental phases are identified as honeycomb alloys Al3Ge3/Al(111)(r7xr7) and Al3Ge4/Al(111)(3x3), by combining ab initio evolutionary simulations, RPA calculations, and available experimental data from scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED). Al3Ge4/Al(111)(3x3) is an interesting structure with a vacancy in the substrate, which accounts for the dark clover pattern in the experimental STM image. Our results clarify the structural controversy of the Ge/Al(111) system and indicate the fabrication of germanene may remain challenging.
