Thermally activated diffusion and lattice relaxation in (Si)GeSn materials
Thermally activated diffusion and lattice relaxation in (Si)GeSn materials
复制标题
(Si)GeSn 材料中的热激活扩散和晶格弛豫
作者：
N. von den Driesch;S. Wirths;R. Troitsch;G. Mussler;U. Breuer;O. Moutanabbir;D. Grützmacher;D. Buca
锗锡（GeSn）合金由于其直接带隙和与现有硅基电子器件的兼容性而成为未来光电子学、能量收集和纳米电子学的有前途的材料。然而，它们的亚稳性带来了重大挑战，需要对其热行为进行深入研究。从这个角度来看，这项工作解决了相互扩散过程中的热退火的假晶GeSn二元和SiGeSn三元合金。在这两个系统中，最初的假晶层放松退火后，完全通过热诱导扩散质量转移的Sn。系统的生长后退火实验揭示了在低于600°C的温度下表现出的增强的Sn和Si扩散机制。放大的低温扩散和观察到的二元和三元之间的细微差异暗示了Si-Ge-Sn材料系统作为相分离的最重要驱动力的独特亚稳性。
Germanium-Tin (GeSn) alloys have emerged as a promising material for future optoelectronics, energy harvesting and nanoelectronics owing to their direct bandgap and compatibility with existing Si-based electronics. Yet, their metastability poses significant challenges calling for in-depth investigations of their thermal behavior. With this perspective, this work addresses the interdiffusion processes throughout thermal annealing of pseudomorphic GeSn binary and SiGeSn ternary alloys. In both systems, the initially pseudomorphic layers are relaxed upon annealing exclusively via thermally induced diffusional mass transfer of Sn. Systematic post-growth annealing experiments reveal enhanced Sn and Si diffusion regimes that manifest at temperatures below 600°C. The amplified low-temperature diffusion and the observation of only subtle differences between binary and ternary hint at the unique metastability of the Si-Ge-Sn material system as the most important driving force for phase separation.