Abstract：
Manipulation of physical properties in multidimensional tunable moiré superlattice systems is a key focus in nanophotonics, especially for interlayer excitons (IXs) in two-dimensional materials. However, the impact of defects on IXs remains unclear. Here, we thoroughly study the optical properties of WS2/WSe2 heterobilayers with varying defect densities. Low-temperature photoluminescence (PL) characterizations reveal that the low-energy IXs are more susceptible to defects compared to the high-energy IXs. The low-energy IXs also show much faster PL quenching rate with temperature, faster peak width broadening rate with laser power, shorter lifetime, and lower circular polarization compared to the low-energy IXs in the region with fewer defects. These effects are attributed to the combined effects of increased electron scattering, exciton-phonon interactions, and nonradiative channels introduced by the defects. Our findings aid in optimizing moiré superlattice structures.
摘要：
在多维可调谐莫尔超晶格系统中对物理性质的操纵是纳米光子学中的一个关键焦点，特别是对于二维材料中的层间激子（IXs）。然而,缺陷对IXs的影响尚不清楚。这里,我们深入研究了具有不同缺陷密度的WS2/WSe2异质双层的光学性质。低温光致发光（PL）表征表明，与高能IXs相比，低能IXs更容易受到缺陷的影响。低能IXs也显示出更快的PL淬火速率随温度变化，更快的峰宽加宽率与激光功率，更短的寿命，与缺陷较少的区域中的低能IX相比，圆极化较低。这些效应归因于电子散射增加的综合效应，激子-声子相互作用，以及缺陷引入的非辐射通道。我们的发现有助于优化莫尔超晶格结构。
