Yin Xinmao, Yang Ming, Tang Chi Sin, Wang Qixing, Xu Lei, Wu Jing, Trevisanutto Paolo Emilio, Zeng Shengwei, Chin Xin Yu, Asmara Teguh Citra, Feng Yuan Ping, Ariando Ariando, Chhowalla Manish, Wang Shi Jie, Zhang Wenjing, Rusydi Andrivo, Wee Andrew T S
International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology Shenzhen University Shenzhen 518060 China.
Department of Physics Faculty of Science National University of Singapore Singapore 117542 Singapore.
Adv Sci (Weinh). 2019 Apr 29;6(12):1900446. doi: 10.1002/advs.201900446. eCollection 2019 Jun 19.
The exciton, a quasi-particle that creates a bound state of an electron and a hole, is typically found in semiconductors. It has attracted major attention in the context of both fundamental science and practical applications. Transition metal dichalcogenides (TMDs) are a new class of 2D materials that include direct band-gap semiconductors with strong spin-orbit coupling and many-body interactions. Manipulating new excitons in semiconducting TMDs could generate a novel means of application in nanodevices. Here, the observation of high-energy excitonic peaks in the monolayer-MoS on a SrTiO heterointerface generated by a new complex mechanism is reported, based on a comprehensive study that comprises temperature-dependent optical spectroscopies and first-principles calculations. The appearance of these excitons is attributed to the change in many-body interactions that occurs alongside the interfacial orbital hybridization and spin-orbit coupling brought about by the excitonic effect propagated from the substrate. This has further led to the formation of a Fermi-surface feature at the interface. The results provide an atomic-scale understanding of the heterointerface between monolayer-TMDs and perovskite oxide and highlight the importance of spin-orbit-charge-lattice coupling on the intrinsic properties of atomic-layer heterostructures, which open up a way to manipulate the excitonic effects in monolayer TMDs via an interfacial system.
激子是一种能使电子和空穴形成束缚态的准粒子，通常存在于半导体中。它在基础科学和实际应用领域都引起了广泛关注。过渡金属二硫属化物（TMDs）是一类新型二维材料，包括具有强自旋轨道耦合和多体相互作用的直接带隙半导体。在半导体TMDs中操控新型激子可为纳米器件带来一种全新的应用方式。在此，基于一项综合研究（包括温度相关光谱学和第一性原理计算），报道了在由一种新的复杂机制产生的SrTiO异质界面上的单层MoS中高能激子峰的观测结果。这些激子的出现归因于多体相互作用的变化，这种变化伴随着由衬底传播的激子效应所引发的界面轨道杂化和自旋轨道耦合而发生。这进一步导致了界面处费米面特征的形成。这些结果提供了对单层TMDs与钙钛矿氧化物之间异质界面的原子尺度理解，并突出了自旋轨道 - 电荷 - 晶格耦合对原子层异质结构本征特性的重要性，这为通过界面系统操控单层TMDs中的激子效应开辟了一条道路。
