Many applications of transition metal dichalcogenides (TMDs) involve transfer to functional substrates that can strongly impact their optical and electronic properties. We investigate the impact that substrate interactions have on free carrier densities and defect-related excitonic (X^D) emission from MoS₂ monolayers grown by metal–organic chemical vapor deposition. C-plane sapphire substrates mimic common hydroxyl-terminated substrates. We demonstrate that transferring MoS₂ monolayers to pristine c-plane sapphire dramatically increases the free electron density within MoS₂ layers, quenches X^D emission, and accelerates exciton recombination at the optical band edge. In contrast, transferring MoS₂ monolayers onto inert hexagonal boron nitride (h-BN) has no measurable influence on these properties. Our findings demonstrate the promise of utilizing substrate engineering to control charge doping interactions and to quench broad X^D background emission features that can influence the purity of single photon emitters in TMDs being developed for quantum photonic applications.

中文翻译：

---

衬底诱导电荷掺杂对单层 MoS2 缺陷相关激子发射的影响


过渡金属二硫属化物 (TMD) 的许多应用涉及转移到功能基材上，这会强烈影响其光学和电子性能。我们研究了基底相互作用对金属有机化学气相沉积生长的 MoS ₂单层的自由载流子密度和缺陷相关激子 (X ^D ) 发射的影响。 C 面蓝宝石衬底模仿常见的羟基封端衬底。我们证明，将 MoS ₂单层转移到原始 c 面蓝宝石上可显着增加 MoS ₂层内的自由电子密度，淬灭^XD发射，并加速光带边缘处的激子复合。相比之下，将MoS ₂单层转移到惰性六方氮化硼(h-BN)上对这些性能没有可测量的影响。我们的研究结果证明了利用衬底工程来控制电荷掺杂相互作用和淬灭宽^XD背景发射特征的前景，这些特征可以影响为量子光子应用开发的 TMD 中单光子发射器的纯度。