Ghukasyan Ara, Goktas Nebile Isik, Dubrovskii Vladimir G, LaPierre Ray R
Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada L8S4L7.
Faculty of Physics, St. Petersburg State University, Universitetskaya Emb. 13B, 199034 St. Petersburg, Russia.
Nano Lett. 2022 Feb 9;22(3):1345-1349. doi: 10.1021/acs.nanolett.1c04680. Epub 2022 Jan 28.
Twinning superlattices (TSLs) are a growing class of semiconductor structures proposed as a means of phonon and optical engineering in nanowires (NWs). In this work, we examine TSL formation in Te-doped GaAs NWs grown by a self-assisted vapor-liquid-solid mechanism (with a Ga droplet as the seed particle), using selective-area molecular beam epitaxy. In these NWs, the TSL structure is comprised of alternating zincblende twins, whose formation is promoted by the introduction of Te dopants. Using transmission electron microscopy, we investigated the crystal structure of NWs across various growth conditions (V/III flux ratio, temperature), finding periodic TSLs only at the low V/III flux ratio of 0.5 and intermediate growth temperatures of 492 to 537 °C. These results are explained by a kinetic growth model based on the diffusion flux feeding the Ga droplet.
孪晶超晶格（TSLs）是一类不断发展的半导体结构，被提议作为纳米线（NWs）中声子和光学工程的一种手段。在这项工作中，我们使用选择性区域分子束外延技术，研究了通过自辅助气-液-固机制（以Ga液滴作为籽晶颗粒）生长的掺Te的GaAs纳米线中TSL的形成。在这些纳米线中，TSL结构由交替的闪锌矿孪晶组成，Te掺杂剂的引入促进了孪晶的形成。我们使用透射电子显微镜研究了在各种生长条件（V/III通量比、温度）下纳米线的晶体结构，发现仅在低V/III通量比0.5和492至537°C的中间生长温度下存在周期性TSL。这些结果由基于向Ga液滴供料的扩散通量的动力学生长模型来解释。
