Security of a printed matter is enhanced, and a visual image is made to clear if a latent image formed by a coat printed on a matter to be printed for a security enhancement of the printed matter becomes the visual image. A security ink pigment contains a powder. A main constituent of the powder is a perovskite-type oxide. The perovskite-type oxide has a composition expressed as a general formula of ABO.sub.3. A is mainly made of Ba. B is mainly made of Sn. The powder emits infrared fluorescence when being irradiated with ultraviolet excitation light. The perovskite-type oxide has a crystal lattice constant having a difference equal to or smaller than 0.002 angstrom from a theoretical crystal lattice constant of the perovskite-type oxide having a composition expressed as a composition formula of BaSnO.sub.3.

An organic-inorganic perovskite CH.sub.3NH.sub.3PbI.sub.3 nanowire showing a length-width aspect ratio from 5-400 up to 10.sup.9 and a width-height ratio of 1-100 up to 1-10000. Further, the invention is embodied as a process for making the nanowire wherein at least a polar aprotic solvents is used, the polar aprotic solvent being at least one from the list comprising DMF, DMSO, and DMAc solvents.

Security of a printed matter is enhanced, a coat printed on a matter to be printed for a security enhancement of the printed matter is printed by a normal printing process, and the coat is flattened and smoothed. A security ink pigment contains a powder. A main constituent of the powder is a perovskite-type oxide. The perovskite-type oxide has a composition expressed as a general formula of ABO.sub.3. A is mainly made of Ba. B is mainly made of Sn. A median diameter of the powder is equal to or smaller than 10 m. The powder emits infrared fluorescence when being irradiated with ultraviolet excitation light.

Lithium-containing thiostannate spinel compounds having the formula Li.sub.2M.sub.1+xSn.sub.3?xS.sub.8, where x is 0 or 1 and M is Mg, Fe, Mn, Ni, Ga, In, or a combination thereof; or the formula Li.sub.1.66CuSn.sub.3.33S.sub.8 are provided. Methods and devices for detecting incident neutrons and alpha-particles using the compounds are also provided. For thermal neutron detection applications, the compounds can be enriched with lithium-6 isotope (.sup.6Li) to enhance their neutron detecting capabilities.

A thermoelectric material containing a dichalcogenide compound represented by Formula 1 and having low thermoelectric conductivity and high Seebeck coefficient:
R.sub.aT.sub.bX.sub.2-nY.sub.n(1)
wherein R is a rare earth element, T includes at least one element selected from the group consisting of Group 1 elements, Group 2 elements, and a transition metal, X includes at least one element selected from the group consisting of S, Se, and Te, Y is different from X and includes at least one element selected from the group consisting of S, Se, Te, P, As, Sb, Bi, C, Si, Ge, Sn, B, Al, Ga and In, a is greater than 0 and less than or equal to 1, b is greater than or equal to 0 and less than 1, and n is greater than or equal to 0 and less than 2.

Provided are ITO particles having a non-rectangular parallelepiped shape and an aligned crystal orientation inside particles.

A chalcogen-containing compound of the following Chemical Formula 1 which exhibits excellent phase stability even at a low temperature, particularly at a temperature corresponding to an operating temperature of a thermoelectric element, and also exhibits a significantly superior power factor and thermoelectric performance index due to its excellent electrical conductivity and low thermal conductivity caused by its unique crystal lattice structure, a method for preparing the same, and a thermoelectric element including the same. [Chemical Formula 1]V.sub.1-2xSn.sub.4Bi.sub.2-xAg.sub.3xSe.sub.7, wherein V is vacancy and 0<x<0.5.

Various embodiments disclosed related to organic or inorganic metal halide perovskites formed via cation exchange and photovoltaic applications thereof. The present invention provides a method of forming an organic or inorganic metal halide perovskite including cation exchanging a hydrocarbylammonium metal halide with a salt comprising an organic or inorganic cation that exchanges with the hydrocarbylammonium cation of the hydrocarbylammonium metal halide, to form the organic or inorganic metal halide perovskite.

Disclosed are a single-source precursor for synthesizing metal chalcogenide nanoparticles for producing a light absorption layer of solar cells comprising a Group VI element linked as a ligand to any one metal selected from the group consisting of copper (Cu), zinc (Zn) and tin (Sn), metal chalcogenide nanoparticles produced by heat-treating at least one type of the single-source precursor, a method of preparing the same, a thin film produced using the same and a method of producing the thin film.

Disclosed are a single-source precursor for synthesizing metal chalcogenide nanoparticles for producing a light absorption layer of solar cells comprising a Group VI element linked as a ligand to any one metal selected from the group consisting of copper (Cu), zinc (Zn) and tin (Sn), metal chalcogenide nanoparticles produced by heat-treating at least one type of the single-source precursor, a method of preparing the same, a thin film produced using the same and a method of producing the thin film.