Skapas Martynas, Luna Esperanza, Stanionytė Sandra, Graser Karl, Butkutė Renata
Center for Physical Science and Technology, Saulėtekio av. 3, Vilnius LT-10257, Lithuania.
Paul Drude Institutu Solid State Electronics, Hausvogteiplatz 5-7, Berlin DE-10117, Germany.
ACS Omega. 2025 Mar 6;10(10):10432-10437. doi: 10.1021/acsomega.4c10631. eCollection 2025 Mar 18.
An in situ transmission electron microscopy study of Bi quantum dot (QD) formation in an annealed GaAsBi/AlAs multiple quantum well (MQW) structure is presented in this work. The investigated structure, containing two GaAsBi QWs and embedded in an AlGaAs parabolic quantum barrier (PQB), was grown on semi-insulating GaAs (100) and was transferred onto an in situ heating holder (DENS solutions) and heated up to 650 °C. Sample evolution was continuously recorded in situ in bright-field STEM mode. The analysis revealed that QD formation occurs at lower annealing temperatures in case of heating of lamella than in bulk. In addition, we find that the mechanism governing Bi QD formation is different in the in situ TEM experiment compared to bulk ex-situ annealing. Comparison of the and annealed structures, as well as in-depth postannealed structure TEM analysis, is presented.
本文介绍了一项关于在退火的GaAsBi/AlAs多量子阱（MQW）结构中Bi量子点（QD）形成的原位透射电子显微镜研究。所研究的结构包含两个GaAsBi量子阱并嵌入AlGaAs抛物量子势垒（PQB）中，生长在半绝缘GaAs（100）上，并转移到原位加热支架（DENS解决方案）上，加热至650°C。在明场STEM模式下原位连续记录样品的演变过程。分析表明，与整体加热相比，薄片加热时量子点形成发生在较低的退火温度下。此外，我们发现与整体非原位退火相比，原位TEM实验中Bi量子点形成的机制有所不同。文中还给出了550°C和650°C退火结构的比较以及退火后结构的深入TEM分析。
