论文标题
了解2D混合MOS2/WSE2异质结构中介电特性，分离距离和频带比对的影响
Understanding the Effects of Dielectric Property, Separation Distance, and Band Alignment on Interlayer Excitons in 2D Hybrid MoS2/WSe2 Heterostructures
论文作者
论文摘要
来自过渡金属二甲元化（TMDC）半导体的二维（2D）范德华异质结构显示出具有非凡特性的新的空间分开激子。已经对层间激子（XI）进行了广泛的研究，但是调节XI的机制仍未得到充分了解。在这里，我们介绍了几个有机层膜的混合异质结构MOS2/Organic/WSE2，以研究XI的结合能。我们发现，由于TMDC层之间的介电常数降低和更大的分离距离，因此，准粒子的介电筛选通过有机分子减少。结果，在层间发射中观察到明显的蓝光。我们还发现，在异质方面的频段对齐至关重要。当有机层提供交错的能量状态时，层间电荷转移可以从隧道转移到带辅助的转移，从而进一步增加了XI发射能，因此XI发射能由于较强的偶极相互作用而导致。 XI的形成也可能被电子或孔捕获分子显着抑制。这些发现对于实现基于XI的光电学应该很有用。
Two dimensional (2D) van der Waals heterostructures from transition metal dichalcogenide (TMDC) semiconductors show a new class of spatially separate excitons with extraordinary properties. The interlayer excitons (XI) have been studied extensively, yet the mechanisms that modulate XI are still not well understood. Here, we introduce several organic-layer-embedded hybrid heterostructures, MoS2/organic/WSe2, to study the binding energy of XI. We discover that the dielectric screening of the quasi-particle is reduced with organic molecules due to decreased dielectric constant and greater separation distance between the TMDC layers. As a result, a distinct blueshift is observed in interlayer emission. We also find that the band alignment at the heterointerface is critical. When the organic layer provides a staggered energy state, interlayer charge transfer can transition from tunneling to band-assisted transfer, further increasing XI emission energies due to a stronger dipolar interaction. The formation of XI may also be significantly suppressed with electron or hole trapping molecules. These findings should be useful in realizing XI-based optoelectronics.
