A low temperature (60 °C) encapsulation process based on a single thin (16 nm) coating of Al ₂ O ₃ prepared by atomic layer deposition.

The lack of scalable-methods for the growth of 2D MoS₂ crystals, an identified emerging material with applications ranging from electronics to energy storage, is a current bottleneck against its large-scale deployment. We report here a two-step ALD route with new organometallic precursors, Mo(NMe₂)₄ and 1,2-ethanedithiol (HS(CH₂)₂SH) which consists in the layer-by-layer deposition of an amorphous surface Mo(IV) thiolate at 50 °C, followed by a subsequent annealing at higher temperature leading to ultra-thin MoS₂ nanocrystals (∼20 nm-large) in the 1–2 monolayer range. In contrast to the usual high-temperature growth of 2D dichalcogenides, where nucleation is the key parameter to control both thickness and uniformity, our novel two-step ALD approach enables chemical control over these two parameters, the growth of 2D MoS₂ crystals upon annealing being ensured by spatial confinement and facilitated by the formation of a buffer oxysulfide interlayer.

Graphene grown via chemical vapour deposition (CVD) on copper foil has emerged as a high-quality, scalable material, that can be easily integrated on technologically relevant platforms to develop promising applications in the fields of optoelectronics and photonics. Most of these applications require low-contaminated high-mobility graphene (i.e., approaching 10 000 cm² V⁻¹ s⁻¹ at room temperature) to reduce device losses and implement compact device design. To date, these mobility values are only obtained when suspending or encapsulating graphene. Here, we demonstrate a rapid, facile, and scalable cleaning process, that yields high-mobility graphene directly on the most common technologically relevant substrate: silicon dioxide on silicon (SiO₂/Si). Atomic force microscopy (AFM) and spatially-resolved X-ray photoelectron spectroscopy (XPS) demonstrate that this approach is instrumental to rapidly eliminate most of the polymeric residues which remain on graphene after transfer and fabrication and that have adverse effects on its electrical properties. Raman measurements show a significant reduction of graphene doping and strain. Transport measurements of 50 Hall bars (HBs) yield hole mobility μ_h up to ∼9000 cm² V⁻¹ s⁻¹ and electron mobility μ_e up to ∼8000 cm² V⁻¹ s⁻¹, with average values μ_h ∼ 7500 cm² V⁻¹ s⁻¹ and μ_e ∼ 6300 cm² V⁻¹ s⁻¹. The carrier mobility of ultraclean graphene reaches values nearly double than those measured in graphene processed with acetone cleaning, which is the method widely adopted in the field. Notably, these mobility values are obtained over large-scale and without encapsulation, thus paving the way to the adoption of graphene in optoelectronics and photonics.

In this paper, we report on a continuous-flow microreactor process to prepare ZnO quantum dots (QDs) with widely tunable particle size and photoluminescence emission wavelengths. X-ray diffraction, electron diffraction, UV-vis, photoluminescence and transmission electron microscopy measurements were used to characterize the synthesized ZnO QDs. By varying operating conditions (temperature, flow rate) or the capping ligand, ZnO QDs with diameters ranging from 3.6 to 5.2 nm and fluorescence maxima from 500 to 560 nm were prepared. Results obtained show that low reaction temperatures (20 or 35 °C), high flow rates and the use of propionic acid as a stabilizing agent are favorable for the production of ZnO QDs with high photoluminescence quantum yields (up to 30%).

Efficient semi‐transparent solar cells can extend the adoption of photovoltaics beyond standard utility‐scale, commercial, or residential applications. Halide perovskites are particularly suitable in this respect owing to their tunable bandgap. The main drawbacks in the development of transparent perovskite solar cells are the high open‐circuit voltage (V_oc) deficit and the difficulties in depositing high‐quality thin films over large area substrates, given the low solubility of bromide and chloride precursors. In this work, passivation strategies are developed for the high bandgap Br perovskite able to reduce charge recombination and consequently improve the V_oc. The study demonstrates 1 cm² perovskite solar cells with V_oc up to 1.73 V (1.83 eV Quasi Fermi Level Splitting) and a PCE of 8.1%. The average visible transmittance (AVT) exceeds 70% by means of a bifacial light management and a record light utilization efficiency (LUE) of 5.72 is achieved. Moreover, the potential use of the technology is evaluated toward Internet of Things (IoT) application owing to a bifaciality factor of 87% along with 17% PCE under indoor lighting. Finally, the up‐scaling is demonstrated by fabricating 20 cm² active area modules with PCE of 7.3% and V_oc per cell up to 1.65 V.