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Mixed‐dimensional systems host interesting phenomena that involve electron and ion transport along or across the interface, with promising applications in optoelectronic and electrochemical devices. Herein, a heterosystem consisting of a graphene monolayer with a colloidal Ag2S nanocrystal film atop, in which both ions and electrons are involved in photoelectrical effects, is studied. An investigation of the transport at the interface in different configurations by using a phototransistor configuration with graphene as a charge‐transport layer and semiconductor nanocrystals as a light‐sensitive layer is performed. The key feature of charge transfer is investigated as a function of gate voltage, frequency, and incident light power. A simple analytical model of the photoresponse is developed, to gain information on the device operation, revealing that the nanocrystals transfer electrons to graphene in the dark, but the opposite process occurs upon illumination. A frequency‐dependence analysis suggests a fractal interface between the two materials. This interface can be modified using solid‐state electrochemical reactions, leading to the formation of metallic Ag particles, which affect the graphene properties by additional doping, while keeping the photoresponse. Overall, these results provide analytical tools and guidelines for the evaluation of coupled electron/ion transport in hybrid systems. [ABSTRACT FROM AUTHOR]

The fabrication of electrochemical double-layer capacitors (EDLCs) with high areal capacitance relies on the use of elevated mass loadings of highly porous active materials. Herein, we demonstrate a high-throughput manufacturing of graphene/carbon nanotubes hybrid EDLCs. The wet-jet milling (WJM) method is exploited to exfoliate the graphite into single-few- layer graphene flakes (WJM-G) in industrial volumes (production rate ca. 0.5 kg/day). Commercial single-/double-walled carbon nanotubes (SDWCNTs) are mixed with graphene flakes in order to act as spacers between the flakes during their film formation. The WJM-G/SDWCNTs films are obtained by one-step vacuum filtration of the material dispersions, resulting in self-standing, metal- and binder-free flexible EDLC electrodes with high active material mass loadings up to around 30 mgcm-2. The corresponding symmetric WJM-G/SDWCNTs EDLCs exhibit electrode energy densities of 539 μWhcm-2 at 1.3 mWcm-2 and operating power densities up to 532 mWcm-2 (outperforming most of the reported EDLC technologies). The EDCLs show excellent cycling stability and outstanding flexibility even in highly folded states (up to 180°). [ABSTRACT FROM AUTHOR]

Spintronic devices require materials that facilitate effective spin transport, generation, and detection. In this regard, graphene emerges as an ideal candidate for long‐distance spin transport owing to its minimal spin‐orbit coupling, which, however, limits its capacity for effective spin manipulation. This problem can be overcome by putting spin‐orbit coupling materials in close contact with graphene leading to spin‐orbit proximity and, consequently, efficient spin‐to‐charge conversion through mechanisms such as the spin Hall effect. Here, the gate‐dependent spin Hall effect in trilayer graphene proximitized with tin sulfide (SnS) is reported and quantified, a group‐IV monochalcogenide that has recently been predicted to be a viable alternative to transition‐metal dichalcogenides for inducing strong spin‐orbit coupling in graphene. The spin Hall angle exhibits a maximum around the charge neutrality point of graphene up to room temperature. The findings expand the library of materials that induce spin‐orbit coupling in graphene to a new class, group‐IV monochalcogenides, thereby highlighting the potential of 2D materials to pave the way for the development of innovative spin‐based devices and future technological applications. [ABSTRACT FROM AUTHOR]

The miniaturization of energy storage units is pivotal for the development of next‐generation portable electronic devices. Micro‐supercapacitors (MSCs) hold great potential to work as on‐chip micro‐power sources and energy storage units complementing batteries and energy harvester systems. Scalable production of supercapacitor materials with cost‐effective and high‐throughput processing methods is crucial for the widespread application of MSCs. Here, wet‐jet milling exfoliation of graphite is reported to scale up the production of graphene as a supercapacitor material. The formulation of aqueous/alcohol‐based graphene inks allows metal‐free, flexible MSCs to be screen‐printed. These MSCs exhibit areal capacitance (Careal) values up to 1.324 mF cm−2 (5.296 mF cm−2 for a single electrode), corresponding to an outstanding volumetric capacitance (Cvol) of 0.490 F cm−3 (1.961 F cm−3 for a single electrode). The screen‐printed MSCs can operate up to a power density above 20 mW cm−2 at an energy density of 0.064 µWh cm−2. The devices exhibit excellent cycling stability over charge–discharge cycling (10 000 cycles), bending cycling (100 cycles at a bending radius of 1 cm) and folding (up to angles of 180°). Moreover, ethylene vinyl acetate‐encapsulated MSCs retain their electrochemical properties after a home‐laundry cycle, providing waterproof and washable properties for prospective application in wearable electronics. Single‐/few‐layer graphene flakes, produced via scalable wet‐jet milling exfoliation of graphite, are used as the active material for micro‐supercapacitors (MSCs). The formulation of aqueous‐alcohol graphene inks, as well as the addition of carbon nanotubes, allows for the interdigitated structure to be screen‐printed on plastic substrates for metal‐free, flexible, solid‐state, and washable MSCs with high areal performance. [ABSTRACT FROM AUTHOR]