论文标题
单层中的中性和充电的深色激子WS $ _2 $
Neutral and charged dark excitons in monolayer WS$_2$
论文作者
论文摘要
低温和极化解析的磁性光致发光实验用于研究深度$ _2 $的单层中深色激子和深色Trions的性质，该单层包含在Hexagonal BN（HBN）中。我们发现，该系统是$ n $ type掺杂的半导体，而黑暗的trions主导了发射光谱。根据先前对WSE $ _2 $的研究，我们通过其极化特性确定了库仑交换相互作用耦合的中性深色和灰色激子，而对于深色Trions来说，没有观察到类似的效果。相对于单层平面，将磁场应用于垂直和并行配置，我们确定深色Trions的G因子为$ g \ sim $ -8.6。它们的衰减速率接近0.5 ns，比明亮的激子长2个数量级以上。
Low temperature and polarization resolved magneto-photoluminescence experiments are used to investigate the properties of dark excitons and dark trions in a monolayer of WS$_2$ encapsulated in hexagonal BN (hBN). We find that this system is an $n$-type doped semiconductor and that dark trions dominate the emission spectrum. In line with previous studies on WSe$_2$, we identify the Coulomb exchange interaction coupled neutral dark and grey excitons through their polarization properties, while an analogous effect is not observed for dark trions. Applying the magnetic field in both perpendicular and parallel configurations with respect to the monolayer plane, we determine the g-factor of dark trions to be $g\sim$-8.6. Their decay rate is close to 0.5 ns, more than 2 orders of magnitude longer than that of bright excitons.
