Solution-processed semiconducting transition metal dichalcogenides (TMDs) are at the centre of an ever-increasing research effort in printed (opto)electronics. However, device performance is limited by structural defects resulting from the exfoliation process and poor inter-flake electronic connectivity.Here, we report a new molecular strategy to boost the electrical performance of TMD-based devices via the use of dithiolated conjugated molecules, to simultaneously heal sulfur vacancies in solutionprocessed transition metal disulfides (MS2) and covalently bridge adjacent flakes, thereby promoting percolation pathways for the charge transport. We achieve a reproducible increase by one order-ofmagnitude in field-effect mobility (µFE), current ratios (ION / IOFF), and switching times (τS) of liquid-gated transistors, reaching 10 -2 cm 2 V -1 s -1 , 10 4 , and 18 ms, respectively. Our functionalization strategy is an universal route to simultaneously enhance the electronic connectivity in MS2 networks and tailor on demand their physicochemical properties according to the envisioned applications.

2D materials possess exceptional physical and chemical properties that render them appealing components for numerous potential applications in (opto)electronics, energy storage, sensing, and biomedicine. However, such unique properties are hardly tunable or modifiable. The functionalization of 2D crystals with molecules constitutes a powerful strategy to adjust and modulate their properties, by also imparting them new functions. In this framework, the combination of 2D materials with photosensitive molecules is a viable route for harnessing their light‐responsive nature. The latter takes full advantage of the extremely high sensitivity of 2D materials to subtle changes in the local environment and the capacity of photosensitive molecules to modify their intrinsic properties when exposed to electromagnetic fields. The hybrid molecule–2D materials can preserve the unique optical and electrical properties of 2D layers and can exhibit additional light‐tunable features. In this Progress Report, the protocols that can be pursued for the 2D material functionalization and switching mechanisms in photosensitive systems are reviewed, followed by an in‐depth discussion on their tunable optical properties and their exploitation when integrated in novel photoswitchable electronic devices. The opportunities and associated challenges to be tackled for the development of unprecedented and high‐performance light‐responsive devices are discussed.

Graphene is regarded as the ultimate material for future flexible, high-performance and wearable electronics. Herein, we report a novel, robust, all-green, highly reliable (yield ≥ 99%) and up-scalable technology for wearable applications comprising reduced graphene oxide (rGO) thin-films as electroactive component in liquid-gated transistors (LGTs).Although the intrinsic electrical performance of rGO cannot compete with CVD graphene, its ease processability, excellent surface reactivity, and large-area coverage make rGO a formidable material for future flexible and wearable applications. We have established a novel protocol towards the high-yield fabrication of flexible rGO LGTs combining high robustness (>1.5h of continuous operation) with state-of-the-art performances, being similar to those of their rigid counterparts operated under liquid gating, including field-effect mobility of ca. 10 -1 cm 2 V -1 s -1 and transconductance of ca. 25 µS. Permeable membranes have been proved crucial to operate flexible LGTs under mechanical stress and with reduced amounts of solution (< 20 µL). Our rGO LGTs were operated in artificial sweat exploiting two different layouts based on lateral-flow paper fluidics. These approaches pave the road towards future real-time tracking of perspiration via a simple and cost-effective approach. The reported findings contribute to the robust and scalable production of novel graphene-based flexible devices, whose features fulfill the requirements of wearable electronics.Received: ((will be filled in by the editorial staff)) Revised: ((will be filled in by the editorial staff)) Published online: ((will be filled in by the editorial staff))