A product includes a solution comprising Ag.sub.2Se quantum dots in a solvent. The solution is colloidally stable for at least one week. A product includes a solid layer formed of Ag.sub.2Se quantum dots. The layer is at least 100 nm thick. The layer is physically characterized by a substantial absence of defects therein. A process includes forming a solution of Ag.sub.2Se quantum dots and adding at least acetonitrile to the solution. The process further includes separating the Ag.sub.2Se quantum dots from the solution and washing the Ag.sub.2Se quantum dots at least two times in a solution comprising at least acetonitrile. The process further includes redispersing the washed Ag.sub.2Se quantum dots in a nonpolar solvent to create a colloidal suspension.

A solid-state ion conductor includes a compound of Formula 1:
Li.sub.(6-a)x+2y-b*z-6A.sub.1−xM.sup.a.sub.xO.sub.yX.sup.b.sub.z  Formula 1
wherein, in Formula 1, A is an element having an oxidation state of +6, M is an element having an oxidation state of a, wherein a is +2, +3, +4, +5, or a combination thereof, X is an element having an oxidation state of b, wherein b is −1, −3, or a combination thereof, and 2<[(6−a)x+2y−b*z−6]≤6.5, 0≤x≤1, y>0, and z≥0.

In a method for producing nanoparticles of copper selenide, a flowable copper precursor is formed by combining a copper starting material and a ligand, and a flowable selenium precursor is formed by suspending a selenium starting material in a liquid. Then a flowable copper-selenium mixture including a lower-polarity solvent is formed by combining the flowable copper precursor and the flowable selenium precursor. The flowable copper-selenium mixture is conducted through at least one heating unit, and the nanoparticles of copper selenide are isolated in an oxygen-depleted environment. The isolation includes combining a solution containing the nanoparticles of copper selenide and a deoxygenated, higher-polarity solvent to precipitate the nanoparticles.

A method is provided for producing an article which is transparent to near-wave IR, mid-wave and Long-wave multi-spectral and IR wavelength in the region of 0.4 μm to 16 μm. The method includes the steps of (a) Producing ultra-fine powder of CaLa.sub.2S.sub.4 via SPLTS process, (b) followed by pretreatment of the ultra-fine powder under inert and reducing gas conditions including H.sub.2 or Argon or N.sub.2 or H.sub.2/H.sub.2S, H.sub.2S, and mixtures there of (c) followed by sieving the powder in 140 mesh screen and cold pressing the powder at 7000 psi for 7 min. into a disk shaped green body (d) then Cold-Isostatic Pressing (CIP) at 40,000 psi for 5 min in a rubber mold (e) finally sintered article of CaLa.sub.2S.sub.4 disk of 25.4 mm diameter with ultra-high density containing cubic phase of CaLa.sub.2S.sub.4 to yield IR transmission of a peak value of 57% within the IR wavelength range of 2 μm to 16 μm, either by using microwave sintering followed by hot isostatic press or spark plasma sintering followed by hot isostatic press or vacuum sintering at (3×10.sup.−6 torr) followed by hot isostatic press or hot press sintering followed by hot isostatic press and finally followed by mirror polished IR article, is obtained.

Composite nanoparticle compositions and associated nanoparticle assemblies are described herein which, in some embodiments, exhibit enhancements to one or more thermoelectric properties including increases in electrical conductivity and/or Seebeck coefficient and/or decreases in thermal conductivity. In one aspect, a composite nanoparticle composition comprises a semiconductor nanoparticle including a front face and a back face and sidewalls extending between the front and back faces. Metallic nanoparticles are bonded to at least one of the sidewalls establishing a metal-semiconductor junction.

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

A method for obtaining at least one particle, including: (a) preparing solution A including at least one precursor of at least one of Si, B, P, Ge, As, Al, Fe, Ti, Zr, Ni, Zn, Ca, Na, Ba, K, Mg, Pb, Ag, V, Te, Mn, Ir, Sc, Nb, Sn, Ce, Be, Ta, S, Se, N, F, and Cl; (b) preparing aqueous solution B; (c) forming droplets of solution A; (d) forming droplets of solution B; (e) mixing droplets; (f) dispersing mixed droplets in a gas flow; (g) heating dispersed droplets to obtain the at least one particle; (h) cooling the at least one particle; and (i) separating and collecting the at least one particle. The aqueous solution is acidic, neutral, or basic. In step (a) and/or step (b) at least one colloidal suspension of a plurality of nanoparticles is mixed with the solution. Also, a device for implementing the method.

The invention relates to Chevrel-phase materials and methods of preparing these materials utilizing a precursor approach. The Chevrel-phase materials are useful in assembling electrodes, e.g., cathodes, for use in electrochemical cells, such as rechargeable batteries. The Chevrel-phase materials have a general formula of Mo.sub.6Z.sub.8 (Z=sulfur) or Mo.sub.6Z.sup.1.sub.8-yZ.sup.2.sub.y (Z.sup.1=sulfur; Z.sup.2=selenium), and partially cuprated Cu.sub.1Mo.sub.6S.sub.8 as well as partially de-cuprated Cu.sub.1-xMg.sub.xMo.sub.6S.sub.8 and the precursors have a general formula of M.sub.xMo.sub.6Z.sub.8 or M.sub.xMo.sub.6Z.sup.1.sub.8-yZ.sup.2.sub.y, M=Cu. The cathode containing the Chevrel-phase material in accordance with the invention can be combined with a magnesium-containing anode and an electrolyte.

This disclosure relates to the manufacture an alkali metal quaternary crystalline nanomaterial. an alkali metal quaternary crystalline nanomaterial having general Formula A (I.sub.2-II-IV-VI.sub.4); and wherein I is sodium (Na) or lithium (Li), II and IV are Zn or Sn, and VI is a chalcogens selected from the group comprising: sulphur (S), selenium (Se) or tellurium (Te). The crystal phase of the alkali metal quaternary crystalline nanomaterial may be a primitive mixed Cu—Au like structure (PMCA) and may have a space group: P42m. The nanomaterials may be adapted to provide a solar cell. Methods of manufacture are also provided.

Composite nanoparticle compositions and associated nanoparticle assemblies exhibit enhancements to one or more thermoelectric properties including increases in electrical conductivity and/or Seebeck coefficient and/or decreases in thermal conductivity. A composite nanoparticle composition comprises a semiconductor nanoparticle including a front face and a back face and sidewalls extending between the front and back faces. Metallic nanoparticles are bonded to at least one of the sidewalls establishing a metal-semiconductor junction.