论文标题
RES2中的其他激发功能和动量黑暗状态
Additional excitonic features and momentum-dark states in ReS2
论文作者
论文摘要
基于rhenium的过渡金属二分法（TMDS）中的单向内部结构各向异性引入了新的2-D材料类，具有各向异性光学特性。在这项工作中，我们对几层res $ _ {2} $进行了依赖温度，极化分辨的光致发光和反射率测量。我们发现了另外两个激子共振（x $ _ {3} $和x $ _ {4} $），这可以归因于自旋变性状态的分裂。激子物种的强度内振荡器强度x $ _ {1} $和x $ _ {2} $伴随着较弱的对应物x $ _ {3} $和x $ _ {4} $，具有相似的极化方向。为$ _ {2} $获得了平面各向异性介电函数，这对于工程轻质物质耦合对于极化敏感的光电设备至关重要。此外，我们的温度依赖性研究表明，存在低较低动量的黑暗状态，导致在30 K时引起异常的PL强度变化，并使用涉及来自这些状态的声子散射的速率方程模型阐明了该状态。我们对附加激子功能和动量黑暗状态的发现可以阐明res $ _ {2} $的电子带结构的真实性质。
Unidirectional in-plane structural anisotropy in Rhenium-based transition metal dichalcogenides (TMDs) introduces a new class of 2-D materials, exhibiting anisotropic optical properties. In this work, we perform temperature dependent, polarization-resolved photoluminescence and reflectance measurements on several-layer ReS$_{2}$. We discover two additional excitonic resonances (X$_{3}$ and X$_{4}$), which can be attributed to splitting of spin degenerate states. Strong in-plane oscillator strength of exciton species X$_{1}$ and X$_{2}$ are accompanied by weaker counterparts X$_{3}$ and X$_{4}$ with similar polarization orientations. The in-plane anisotropic dielectric function has been obtained for ReS$_{2}$ which is essential for engineering light matter coupling for polarization sensitive optoelectronic devices. Furthermore, our temperature dependent study revealed the existence of low-lying momentum-forbidden dark states causing an anomalous PL intensity variation at 30 K, which has been elucidated using a rate equation model involving phonon scattering from these states. Our findings of the additional excitonic features and the momentum-dark states can shed light on the true nature of the electronic band structure of ReS$_{2}$.
