Institut für Theoretische Physik , Universität Bremen , P.O. Box 330 440, 28334 Bremen , Germany.
Walter Schottky Institut and Physik Department , Technische Universität München , Am Coulombwall 4 , 85748 Garching , Germany.
Nano Lett. 2018 Apr 11;18(4):2725-2732. doi: 10.1021/acs.nanolett.8b00840. Epub 2018 Mar 29.
The electronic and optical properties of monolayer transition-metal dichalcogenides (TMDs) and van der Waals heterostructures are strongly subject to their dielectric environment. In each layer, the field lines of the Coulomb interaction are screened by the adjacent material, which reduces the single-particle band gap as well as exciton and trion binding energies. By combining an electrostatic model for a dielectric heteromultilayered environment with semiconductor many-particle methods, we demonstrate that the electronic and optical properties are sensitive to the interlayer distances on the atomic scale. An analytic treatment is used to provide further insight into how the interlayer gap influences different excitonic transitions. Spectroscopical measurements in combination with a direct solution of a three-particle Schrödinger equation reveal trion binding energies that correctly predict recently measured interlayer distances and shed light on the effect of temperature annealing.
单层过渡金属二卤化物 (TMD) 和范德华异质结构的电子和光学性质强烈依赖于其介电环境。在每个层中，库仑相互作用的场线被相邻材料屏蔽，这降低了单粒子带隙以及激子和三体束缚能。通过将介电异质多层环境的静电模型与半导体多粒子方法相结合，我们证明了电子和光学性质对原子尺度上的层间距离敏感。分析处理用于进一步深入了解层间间隙如何影响不同的激子跃迁。光谱测量与三体薛定谔方程的直接解相结合，揭示了三体束缚能，这些束缚能正确预测了最近测量的层间距离，并阐明了温度退火的影响。
