论文标题
exfoliated WS $ _2 $薄片中的平面外磁场增强大型光致发光
Large photoluminescence enhancement by an out-of-plane magnetic field in exfoliated WS$_2$ flakes
论文作者
论文摘要
我们报告了一个平面外磁场在WS $ {} _ 2 $ flakes $ 4 $ K中引起的大型光致发光增强，与一般面板内的光致发光增强相反。提出了两种增强机制。一种是由磁场引起的限制引起的电子和孔的较大重叠。另一个是$λ$和k谷之间的能量差会通过磁场降低，从而增强了相应的间接转换trions。同时，Trion的LandéG因子被衡量为$ -0.8 $，其绝对值比普通的激子小得多，该激素大约为$ | -4 | $。提出了Trion G系数的模型，证实了LandéG因子的绝对值较小是此$λ$ -K Trion的行为。通过扩展山谷空间，我们认为这项工作可以进一步了解单层过渡金属二分法中的山谷基质。
We report an out-of-plane magnetic field induced large photoluminescence enhancement in WS${}_2$ flakes at $4$ K, in contrast to the photoluminescence enhancement provided by in-plane field in general. Two mechanisms for the enhancement are proposed. One is a larger overlap of electron and hole caused by the magnetic field induced confinement. The other is that the energy difference between $Λ$ and K valleys is reduced by magnetic field, and thus enhancing the corresponding indirect-transition trions. Meanwhile, the Landé g factor of the trion is measured as $-0.8$, whose absolute value is much smaller than normal exciton, which is around $|-4|$. A model for the trion g factor is presented, confirming that the smaller absolute value of Landé g factor is a behavior of this $Λ$-K trion. By extending the valley space, we believe this work provides a further understanding of the valleytronics in monolayer transition metal dichalcogenides.
