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Recently, 2D nanomaterials have received considerable attention in nanomedicine due to their intrinsic optical properties, biocompatibility, and therapeutic effect. Here, 2D germanium telluride (GeTe) nanosheets coated with polyvinylpyrrolidone (PVP) (GeTe‐PVP NSs) developed as theranostic agents are reported that can be used for multispectral optoacoustic tomography (MSOT) and fluorescence imaging and therapy of inflammatory bowel disease (IBD). GeTe‐PVP NSs, fabricated by simple sonication in ethanol and PVP, show broad optical absorption in visible and near‐infrared (NIR) ranges (400–1200 nm) and have intrinsic fluorescence properties. Thus, they provide deeper ex vivo and in vivo MSOT tissue images than gold nanorods or indocyanine green with strong optical absorption in the first NIR window (700–900 nm). In addition, when orally administered to IBD mice, GeTe‐PVP NSs exhibit therapeutic efficacy similar to or higher than sulfasalazine, with strong accumulation at inflammatory colon sites. This demonstrates that oral administration of GeTe‐PVP NSs may be used to treat inflammatory diseases in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

The development of multi‐valued logic devices, which involve switching between more than two states, is one of the promising approaches for overcoming the issues caused by the further scaling down of the current complementary metal‐oxide semiconductor devices. This paper presents ternary devices based on MoS2/h‐BN/graphene heterostructures, in which an active channel of MoS2 is partially aligned with a floating gate of graphene, unlike in the case of typical flash memory devices; thus, they can be regarded as a circuit consisting of a memory device and field‐effect transistor internally connected in parallel. The transfer curves of these devices exhibit two different threshold voltages (Vth) with ternary states ("0," "1," and "2"). Furthermore, the intermediate state can be controlled by oxygen plasma treatment, resulting in a ratio >102 for "1"/"0" states and "2"/"1" states. Thus, these devices can be used to implement a resistive‐load standard ternary inverter, whose output voltage is close to 1, 0.5, and 0 V under the supply voltage of 1 V. In addition, ternary NMIN and NMAX circuits with resistive loads are demonstrated by connecting two ternary inverters in series and parallel, respectively. [ABSTRACT FROM AUTHOR]

Recently, dynamic Schottky diode or p–n junction-based triboelectric nanogenerators (TENGs) which generate direct current were reported. However, most of them exhibited low output voltage because their semiconducting friction layers were directly constructed on an electrode. In this study, we report a "tribodiffusion-driven" TENG, the working mechanism of which differs from previously reported ones. When n-type MoS2 and p-type polypyrrole (PPy) are in contact, electrons and holes diffuse into PPy and MoS2, respectively, contributing to generating output voltages and currents. To increase the number of charges diffusing across the p–n junction, Ag nanoparticles (NPs) and a piezoelectric poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) layer were placed below MoS2. Additionally, PPy was p-doped using Pt NPs. These MoS2-based TENGs exhibited an instantaneous power density of 14.4 mW cm−2 with an external load resistor of 1 MΩ and a transferred charge density of 0.047 μC cm−2 in a single cycle when charging a capacitor. These values are higher than the previously reported values, demonstrating that tribodiffusion-based TENGs can be regarded as another type of TENG. [ABSTRACT FROM AUTHOR]