Monolayer transition metal dichalcogenides (TMDCs) have recently emerged as a host material for localized optically active quantum emitters that generate single photons.(1−5) Here, we investigate fully localized excitons and trions from such TMDC quantum emitters embedded in a van der Waals heterostructure. We use direct electrostatic doping through the vertical heterostructure device assembly to generate quantum confined trions. Distinct spectral jumps as a function of applied voltage bias, and excitation power-dependent charging, demonstrate the observation of the two different excitonic complexes. We also observe a reduction of the intervalley electron–hole exchange interaction in the confined trion due to the addition of an extra electron, which is manifested by a decrease in its fine structure splitting. We further confirm this decrease of exchange interaction for the case of the charged states by a comparative study of the circular polarization resolved photoluminescence from individual excitonic states. The valley polarization selection rules inherited by the localized trions will provide a pathway toward realizing a localized spin-valley-photon interface.

中文翻译：

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电荷可调范德华异质结构中单层WSe ₂中的3D局部Trions

最近，单层过渡金属二硫化碳（TMDC）成为了产生单光子的局部光学活性量子发射体的主体材料。（1-5）在这里，我们研究了嵌入范德华耳中的此类TMDC量子发射体的完全局域的激子和三子。异质结构。我们通过垂直的异质结构器件组装使用直接静电掺杂来生成量子约束的Trion。明显的频谱跳跃与施加的电压偏置以及与激励功率有关的充电的关系，证明了对两种不同的激子复合物的观察。我们还观察到由于添加了额外的电子，在封闭的三元组中，间隔电子与空穴交换的相互作用降低了，这表现为其精细结构分裂的减少。我们通过比较圆极化偏振光从单个激子态的光致发光的比较研究，进一步证实了带电态情况下交换相互作用的这种降低。局域三重子所继承的波谷极化选择规则将为实现局域自旋谷-光子界面提供一条途径。