Abstract: A method for fabricating a composite material includes forming an emulsion mixture of active material particles and graphene emulsion droplets containing immiscible first and second solvents and a solid-state emulsifier of graphene, wherein the first and second solvents are adapted such that the second solvent resides in an interior of the graphene emulsion droplets with the first solvent as an exterior solvent, and the active material particles reside in the interior of the emulsion droplets; wherein a boiling point of the second solvent is lower than that of the first solvent; and drying the emulsion mixture with subsequent evaporation of the second solvent and the first solvent through fractional distillation to form the composite material having each surface of the active material particles conformally coated with said graphene.

Abstract: Preparation of two-dimensional indium selenide, other two-dimensional materials and related compositions via surfactant-free deoxygenated co-solvent systems.

Abstract: This invention discloses a high-modulus, ion-conductive gel electrolyte and methods of producing the gel electrolyte and electrochemical devices. The method for producing the gel electrolyte includes providing a first amount of exfoliated nanosheets of a compound, each nanosheet having a thin carbon coating thereon; preparing a second amount of an ionic liquid; and mixing the first amount of the exfoliated, carbon-coated nanosheets with the second amount of the ionic liquid to form the gel electrolyte.

Abstract: One aspect of this invention relates to hexagonal boron nitride (hBN) ionogel inks using exfoliated hBN nanoplatelets as the solid matrix. The hBN nanoplatelets are produced from bulk hBN powders by liquid-phase exfoliation, allowing printable hBN ionogel inks to be formulated following the addition of an imidazolium ionic liquid and ethyl lactate. The resulting inks are reliably printed with variable patterns and controllable thicknesses by aerosol jet printing, resulting in hBN ionogels that possess high room-temperature ionic conductivities and storage moduli of >3 mS cm?1 and >1 MPa, respectively. By integrating the hBN ionogel with printed semiconductors and electrical contacts, fully-printed thin-film transistors with operating voltages below 1 V are demonstrated on polyimide films. These devices exhibit desirable electrical performance and robust mechanical tolerance against repeated bending cycles, thus confirming the suitability of hBN ionogels for printed and flexible electronics.

Abstract: The invention discloses a megasonically exfoliated two-dimensional (2D) nanomaterial ink. The megasonically exfoliated 2D nanomaterial ink is then aerosol-jet printed (AJP) onto printed graphene electrodes to achieve all-AJP, flexible photodetectors. The 2D nanomaterial AJP ink is designed with terpineol, a high boiling point solvent, which enables a highly ordered thin-film morphology and also improves the photogenerated charge transport. After printing, the photodetectors are photonically annealed, which provides quasi-ohmic contacts and photoactive channels with responsivities that outperform previously reported all-printed visible photodetectors by over 3 orders of magnitude. Megasonic exfoliation coupled with AJP allows the superlative optoelectronic properties of ultrathin nanosheets to be utilized in the scalable additive manufacturing of mechanically flexible optoelectronics.

Abstract: Methods and systems of fabrication of high resolution, high-throughput electrochemical sensing circuits on a substrate. High resolution electrochemical sensing circuits are printed by an effective additive technique to the substrate. Optionally, post-print annealing converts electrochemically inactive printed graphene into one that is electrochemically active. The printing can be by aerosol jet printing, but is not necessarily limited thereto. An example is inkjet printing and then the post-print annealing. Ink formulation would be adjusted for effectiveness with inkjet printing. Optionally biorecognition agents can be covalently bonded to the printed graphene for the purpose of electrochemical biosensing. High throughput fabrication of high-resolution graphene circuits (feature sizes in the tens of microns <50 ?m) for electrochemical biosensing is possible by chemical functionalization of the graphene surface with a biological agent.

Abstract: One aspect of the invention relates to a method for scalable production of kaolinite nanoplatelets (KNPs) comprising shear-mixing a mixture of bulk kaolinite with ethanol or water and a dispersing agent; centrifuging the shear-mixed mixture to sediment and remove unexfoliated bulk kaolinite, and obtain a supernatant containing the KNPs; flocculating the supernatant with deionized (DI) water or sodium chloride solution, collecting and drying flocculated KNPs; and annealing the flocculated KNPs to decompose and volatilize the remaining dispersing agent, thereby resulting in a partial coating of oxidized amorphous carbon on the surface of the KNPs.

Abstract: This invention in one aspect relates to a method of synthesizing a self-assembled mixed-dimensional heterostructure including 2D metallic borophene and 1D semiconducting armchair-oriented graphene nanoribbons (aGNRs). The method includes depositing boron on a substrate to grow borophene thereon at a substrate temperature in an ultrahigh vacuum (UHV) chamber; sequentially depositing 4,4?-dibromo-p-terphenyl on the borophene grown substrate at room temperature in the UHV chamber to form a composite structure; and controlling multi-step on-surface coupling reactions of the composite structure to self-assemble a borophene/graphene nanoribbon mixed-dimensional heterostructure. The borophene/aGNR lateral heterointerfaces are structurally and electronically abrupt, thus demonstrating atomically well-defined metal-semiconductor heterojunctions.

Abstract: A GHeT includes a bottom gate formed on a substrate; a first dielectric layer (DL) formed on the bottom gate; a monolayer film formed of an atomically thin material on the first DL; a bottom contact (BC) formed on part of the monolayer film; a second DL formed on the BC; a top contact (TC) formed on the second DL on top of the BC; a network of CNTs formed on the TC and the monolayer film, to define an overlap region with the monolayer film; a third DL formed on the CNT network, the monolayer film and the TC; and a top gate formed on the third DL and overlapping with the overlap region. Such GHeT design allows gate tunability of Gaussian peak position, height and width that define Gaussian transfer characteristic, thereby enabling simplified circuit architectures for various spiking neuron functions for emerging neuromorphic applications.

Abstract: This invention discloses high-modulus, ion-conductive gel electrolytes and methods of making the gel electrolytes and electrochemical devices. The gel electrolytes include an ionic liquid and nanosheets mixed in the ionic liquid. The nanosheets in one example include exfoliated hexagonal boron nitride (hBN) nanosheets. Compared to conventional bulk hBN microparticles, exfoliated hBN nanosheets improve the mechanical properties of the gel electrolytes by about 2 orders of magnitude, while retaining high ionic conductivity at room temperature. Moreover, exfoliated hBN nanosheets are compatible with high-voltage cathodes, and impart exceptional thermal stability that allows high-rate operation of solid-state rechargeable lithium-ion batteries at high temperatures.

Abstract: Preparation of two-dimensional indium selenide, other two-dimensional materials and related compositions via surfactant-free deoxygenated co-solvent systems.

Abstract: A composite material and a method for fabricating the same. The composite material includes graphene and active material particles. Each surface of the active material particles is conformally coated with said graphene. The method includes forming a mixture containing an active material, graphene, ethyl cellulose (EC) polymer and multiwalled carbon nanotubes, and thermally annealing the mixture at an annealing temperature in an oxidizing environment to decompose the majority of EC, thereby resulting in the composite material having each active material particle coated with a conformal graphene coating.

Abstract: An electrode for a lithium-ion battery includes a substrate; and a composite deposited on the substrate, wherein the composite comprises layered graphene comprising mono-, bi- and n-layered graphene, wherein n is an integer selected from 3-about 6; and nanoparticles of a material selected from a cathode active material and an anode active material, wherein the surface of each of said nanoparticles is coupled to and conformally coated with said layered graphene, and wherein said layered graphene is not graphene oxide and is not reduced graphene oxide.

Abstract: One aspect of the invention relates to a method for fabricating a memtransistor comprising growing a polycrystalline monolayer film on a substrate, wherein the polycrystalline monolayer film contains grains defining a plurality of grain boundaries thereof; and forming an electrode array on the grown polycrystalline monolayer film, wherein the electrode array has a plurality of electrodes electrically coupled with the polycrystalline monolayer film such that each pair of electrodes defines a channel in the polycrystalline monolayer film therebetween.

Abstract: The invention relates to two dimensional (2D) heterostructures and methods of fabricating the same. The 2D hetero structures are integration of borophene with graphene and 2D lateral and vertical hetero structures with sharp and rotationally commensurate interfaces. The rich bonding configurations of boron indicate that borophene can be integrated into a diverse range of 2D heterostructures.

Abstract: The invention relates to printable ion-conductive and viscosity-tunable inks based on two-dimensional (2D) insulators, forming methods and applications of the inks. The 2D insulating material based printable ink includes at least one solvent; and an exfoliated composition dispersed in the at least one solvent. The exfoliated composition includes a 2D insulating material and a dispersant and stabilizing agent. The printed structures of the 2D insulating material based printable ink possess high ionic conductivity, chemical and thermal stability, and electrically insulating character, which are an ideal set of characteristics for printable battery components such as separators and solid electrolytes.

Abstract: Printable inks based on a 2D semiconductor, such as MoS2, and its applications in fully inkjet-printed optoelectronic devices are disclosed. Specifically, percolating films of MoS2 nanosheets with superlative electrical conductivity (10?2 s m?1) are achieved by tailoring the ink formulation and curing conditions. Based on an ethyl cellulose dispersant, the MoS2 nanosheet ink also offers exceptional viscosity tunability, colloidal stability, and printability on both rigid and flexible substrates. Two distinct classes of photodetectors are fabricated based on the substrate and post-print curing method. While thermal annealing of printed devices on rigid glass substrates leads to a fast photoresponse of 150 ?s, photonically annealed devices on flexible polyimide substrates possess high photoresponsivity exceeding 50 mA/W.

Abstract: A memtransistor includes a top gate electrode and a bottom gate electrode; a polycrystalline monolayer film formed of an atomically thin material disposed between the top gate electrode and the bottom gate electrode; and source and drain electrodes spatial-apart formed on the polycrystalline monolayer film to define a channel in the polycrystalline monolayer film between the source and drain electrodes. The top gate electrode and the bottom gate electrode are capacitively coupled with the channel.

Abstract: One aspect of this invention relates to a method of forming a nanomaterial ink comprising providing an as-prepared (AP) semiconductor ink containing first nanosheets of at least one semiconductor; and megasonically exfoliating the AP semiconductor ink to form a megasonicated semiconductor ink containing second nanosheets of the at least one semiconductor.

Abstract: Printable inks based on a 2D semiconductor, such as MoS2, and its applications in fully inkjet-printed optoelectronic devices are disclosed. Specifically, percolating films of MoS2 nanosheets with superlative electrical conductivity (10?2 s m?1) are achieved by tailoring the ink formulation and curing conditions. Based on an ethyl cellulose dispersant, the MoS2 nanosheet ink also offers exceptional viscosity tunability, colloidal stability, and printability on both rigid and flexible substrates. Two distinct classes of photodetectors are fabricated based on the substrate and post-print curing method. While thermal annealing of printed devices on rigid glass substrates leads to a fast photoresponse of 150 ?s, photonically annealed devices on flexible polyimide substrates possess high photoresponsivity exceeding 50 mA/W.