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The 2D transition metal dichalcogenides attract high research interest due to their electronic properties, and MoS2 is likely the most explored compound of this group. The fabrication of MoS2 thin films by the sulfurization of predeposited MoO3 layers on a c‐plane sapphire substrate by radio frequency magnetron sputtering from stoichiometric MoO3 target is reported. The structure and properties of as‐grown MoO3 and MoS2 layers are characterized by several methods including X‐ray diffraction, grazing‐incidence wide‐angle X‐ray scattering, photoelectron spectroscopy, Raman spectroscopy, and atomic force microscopy. Furthermore, the influence of the crystallographic structure of MoO3 layers on the final MoS2 films is studied. The influence of the crystallographic structure of MoO3 on the resulting MoS2 films is focused. A strong texturation in the c‐axis direction and an indication of a high degree in‐plane orientation of MoS2 thin films on the c‐sapphire substrate is observed. [ABSTRACT FROM AUTHOR]

At present, the power conversion efficiency of single-junction perovskite-based solar cells reaches over 26%. The further efficiency increase of perovskite-based optoelectronic devices is limited mainly by defects, causing the nonradiative recombination of charge carriers. To improve efficiency and ensure reproducible fabrication of high-quality layers, it is crucial to understand the perovskite nucleation and growth mechanism along with associated process control to reduce the defect density. In this study, we investigate the growth kinetics of a promising narrow bandgap perovskite, formamidinium methylammonium lead iodide (FAMAPbI 3 ), for high-performance single-junction solar cells. The temporal evolution of structural and optoelectronic properties during FAMAPbI 3 vacuum codeposition was inspected in real time by grazing-incidence wide-angle X-ray scattering and photoluminescence. Such a combination of analytical techniques unravels the evolution of intrinsic defect density and layer morphology correlated with lattice strain from the early stages of the perovskite deposition.

Molybdenum disulfide (MoS 2 ) few-layer films have gained considerable attention for their possible applications in electronics and optics and also as a promising material for energy conversion and storage. Intercalating alkali metals, such as lithium, offers the opportunity to engineer the electronic properties of MoS 2 . However, the influence of lithium on the growth of MoS 2 layers has not been fully explored. Here, we have studied how lithium affects the structural and optical properties of the MoS 2 few-layer films prepared using a new method based on one-zone sulfurization with Li 2 S as a source of lithium. This method enables incorporation of Li into octahedral and tetrahedral sites of the already prepared MoS 2 films or during MoS 2 formation. Our results discover an important effect of lithium promoting the epitaxial growth and horizontal alignment of the films. Moreover, we have observed a vertical-to-horizontal reorientation in vertically aligned MoS 2 films upon lithiation. The measurements show long-term stability and preserved chemical composition of the horizontally aligned Li-doped MoS 2 ., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Few-layer MoS 2 films are promising candidates for applications in numerous areas, such as photovoltaics, photocatalysis, nanotribology, lithium batteries, hydro-desulfurization catalysis and dry lubricants, especially due to their distinctive electronic, optical, and catalytic properties. In general, two alignments of MoS 2 layers are possible - the horizontal and the vertical one, having different physicochemical properties. Layers of both orientations are conventionally fabricated by a sulfurization of pre-deposited Mo films. So far, the Mo thickness was considered as a critical parameter influencing the final orientation of MoS 2 layers with horizontally and vertically aligned MoS 2 grown from thin (1 nm) and thick (3 nm) Mo films, respectively. Here, we present a fabrication protocol enabling the growth of horizontally or vertically aligned few-layer MoS 2 films utilizing the same Mo thickness of 3 nm. We show that the sulfur vapor is another parameter influencing the growth mechanism, where a sulfurization with higher sulfur vapor pressure leads to vertical MoS 2 layers and slow sulfur evaporation results in horizontally aligned layers for a thicker Mo starting layer., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Few-layer MoS 2 films stay at the forefront of current research of two-dimensional materials. At present, continuous MoS 2 films are prepared by chemical vapor deposition (CVD) techniques. Herein, we present a cost-effective fabrication of the large-area spatially uniform films of few-layer MoS 2 flakes using a modified Langmuir-Schaefer technique. The compression of the liquid-phase exfoliated MoS 2 flakes on the water subphase was used to form a continuous layer, which was subsequently transferred onto a submerged substrate by removing the subphase. After vacuum annealing, the electrical sheet resistance dropped to a level of 10 kΩ/sq, being highly competitive with that of CVD-deposited MoS 2 nanosheet films. In addition, a consistent fabrication protocol of the large-area conductive MoS 2 films was established. The morphology and electrical properties predetermine these films to advanced detecting, sensing, and catalytic applications. A large number of experimental techniques were used to characterize the exfoliated few-layer MoS 2 flakes and to elucidate the formation of the few-layer MoS 2 Langmuir film.