通过超低加速电压下的电子辐照控制单层MoS2中的缺陷产生
Controlled defect production in monolayer MoS2 via electron irradiation at ultralow accelerating voltages
AI总结：
研究发现在超低加速电压（≤5kV）下电子辐照可在单层MoS2中产生缺陷，结合机器学习力场和本征模投影方法模拟拉曼光谱，证实硫空位为缺陷来源，并排除含碳污染物影响，为光子学和量子发射器提供应用。
摘要：
使用电子束辐照可以实现对二维材料中缺陷空间位置和密度的控制。相反，超低加速电压（小于或等于5kV）被用于测量表面形貌，预期不会产生缺陷。我们在这些电压下发现了单层（ML）MoS2中缺陷产生的清晰特征。E'和A1'拉曼模式随电子剂量的演化，以及缺陷激活峰的出现，表明了缺陷的形成。为了在保持密度泛函理论精度的同时模拟真实缺陷分布下MoS2的拉曼光谱，我们结合了用于声子的机器学习力场和用于拉曼张量的本征模投影方法。模拟光谱与实验一致，表明硫空位为可能的缺陷。我们使用对照样品（hBN覆盖和封装的MoS2）解耦了缺陷、掺杂和含碳污染物。我们观察到低温PL猝灭和缺陷峰，并发现含碳污染物不影响缺陷产生。这些研究在光子学和量子发射器中有应用。
英文摘要：
Control on spatial location and density of defects in 2D materials can be achieved using electron beam irradiation. Conversely, ultralow accelerating voltages (less than or equal to 5kV) are used to measure surface morphology, with no expected defect creation. We find clear signatures of defect creation in monolayer (ML) MoS2 at these voltages. Evolution of E' and A1' Raman modes with electron dose, and appearance of defect activated peaks indicate defect formation. To simulate Raman spectra of MoS2 at realistic defect distributions, while retaining density-functional theory accuracy, we combine machine-learning force fields for phonons and eigenmode projection approach for Raman tensors. Simulated spectra agree with experiments, with sulphur vacancies as suggested defects. We decouple defects, doping and carbonaceous contamination using control (hBN covered and encapsulated MoS2) samples. We observe cryogenic PL quenching and defect peaks, and find that carbonaceous contamination does not affect defect creation. These studies have applications in photonics and quantum emitters.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
