论文标题
在可调的Janus WSES单层中识别激子复合物
Identification of exciton complexes in a charge-tuneable Janus WSeS monolayer
论文作者
论文摘要
Janus过渡金属二核苷元单层是完全人造物质，其中一种chalcentogen原子的平面被另一种类型的chalcogen原子取代。理论预测平面外电场，从而产生了长寿的偶极激子，同时保留了均匀的潜在景观中直接带隙光学转变。先前的Janus研究具有广泛的光致发光（> 15 MEV）光谱，使它们的激子起源混淆。在这里，我们以$ \ sim 6 $ MEV光学线宽确定了Janus WSES单层中的中性和负电荷的Intravalley激子过渡。我们将最近开发的合成技术与Janus单层的整合到垂直异质结构中，从而可以控制兴奋剂。此外，磁化测量值表明单层WSE在k点处具有直接的带隙。这项工作为诸如纳米级传感等应用提供了基础，该应用依赖于解决激子的能量转移和光伏能量收集，这需要有效地创建长寿命的激子并集成到垂直异质结构中。
Janus transition-metal dichalcogenide monolayers are fully artificial materials, where one plane of chalcogen atoms is replaced by chalcogen atoms of a different type. Theory predicts an in-built out-of-plane electric field, giving rise to long-lived, dipolar excitons, while preserving direct-bandgap optical transitions in a uniform potential landscape. Previous Janus studies had broad photoluminescence (>15 meV) spectra obfuscating their excitonic origin. Here, we identify the neutral, and negatively charged inter- and intravalley exciton transitions in Janus WSeS monolayer with $\sim 6$ meV optical linewidth. We combine a recently developed synthesis technique, with the integration of Janus monolayers into vertical heterostructures, allowing doping control. Further, magneto-optic measurements indicate that monolayer WSeS has a direct bandgap at the K points. This work provides the foundation for applications such as nanoscale sensing, which relies on resolving excitonic energy shifts, and photo-voltaic energy harvesting, which requires efficient creation of long-lived excitons and integration into vertical heterostructures.
