Lithium-Induced Reorientation of Few-Layer MoS2 Films

Molybdenum disulfide (MoS2) few-layer filmshave gainedconsiderable attention for their possible applications in electronicsand optics and also as a promising material for energy conversionand storage. Intercalating alkali metals, such as lithium, offersthe opportunity to engineer the electronic properties of MoS2. However, the influence of lithium on the growth of MoS2 layers has not been fully explored. Here, we have studied how lithiumaffects the structural and optical properties of the MoS2 few-layer films prepared using a new method based on one-zone sulfurizationwith Li2S as a source of lithium. This method enables incorporationof Li into octahedral and tetrahedral sites of the already preparedMoS(2) films or during MoS2 formation. Our resultsdiscover an important effect of lithium promoting the epitaxial growthand horizontal alignment of the films. Moreover, we have observeda vertical-to-horizontal reorientation in vertically aligned MoS2 films upon lithiation. The measurements show long-term stabilityand preserved chemical composition of the horizontally aligned Li-dopedMoS(2).