Abstract: A light-emitting device comprising: a first electrode, a second electrode facing the first electrode; an emission layer disposed between the first electrode and the second electrode; and a first charge transport layer disposed between the first electrode and the emission layer, wherein a band gap energy of the emission layer and a band gap energy of the first charge transport layer are different from each other, the emission layer comprises a first perovskite compound, and the first charge transport layer consists of a second perovskite compound.

Abstract: A thin film includes a luminescent compound represented by Formula 1 and a random copolymer, wherein the random copolymer includes a first repeating unit including at least one aromatic ring, and a second repeating unit including a heteroatom including at least one lone pair of electrons, [A]n[Q]m[X]l??Formula 1 wherein, in Formula 1, A is a monovalent organic cation, a monovalent inorganic cation, or a combination thereof, Q is a divalent metal cation, a divalent metalloid cation, or a combination thereof, X is at least one monovalent halogen ion, n is an integer from 1 to 3, m is an integer from 1 to 2, and l is an integer from 1 to 5.

Abstract: A luminescent material represented by Formula 1, a method of preparing the same, and a light-emitting device including the same: [A1nA23][B2][X1mX25]??Formula 1 A1, A2, B, X1, X2, n, and m in Formula 1 are as defined in the specification.

Abstract: A method of preparing a light-emitting material, the method including mixing a first precursor solution including a first precursor and a first solvent with a second precursor solution including a second precursor and a second solvent to form a precipitate, and separating the precipitate to obtain a light-emitting material, wherein a solubility of the first precursor in the first solvent may be greater than a solubility of the first precursor in the second solvent, and a solubility of the second precursor in the second solvent may be greater than a solubility of the second precursor in the first solvent. A light-emitting material prepared by the method, and a light-emitting device including the light-emitting material is also described.

Abstract: A thin film includes a luminescent compound represented by Formula 1 and a random copolymer, wherein the random copolymer includes a first repeating unit including at least one aromatic ring, and a second repeating unit including a heteroatom including at least one lone pair of electrons, [A]n[Q]m[X]l??Formula 1 wherein, in Formula 1, A is a monovalent organic cation, a monovalent inorganic cation, or a combination thereof, Q is a divalent metal cation, a divalent metalloid cation, or a combination thereof, X is at least one monovalent halogen ion, n is an integer from 1 to 3, m is an integer from 1 to 2, and l is an integer from 1 to 5.

Abstract: A luminescent material represented by Formula 1, a method of preparing the same, and a light-emitting device including the same: Formula 1 [A1nA23][B2][X1mX25] A1, A2, B, X1, X2, n, and m in Formula 1 are as defined in the specification.

Abstract: A light-emitting device comprising: a first electrode, a second electrode facing the first electrode; an emission layer disposed between the first electrode and the second electrode; and a first charge transport layer disposed between the first electrode and the emission layer, wherein a band gap energy of the emission layer and a band gap energy of the first charge transport layer are different from each other, the emission layer comprises a first perovskite compound, and the first charge transport layer consists of a second perovskite compound.

Abstract: Provided are a luminescent compound represented by Formula 1, a method of preparing the same, and a light-emitting device including the same: [A1nA2(3?n)][B1mB2(2?m)]X5 ??Formula 1 wherein, in Formula 1, A1, A2, B1, B2, n, m, and X are as defined in the specification.

Abstract: A small-scale scrapped tire boiler system for heating a small-scale facility using heat generated by burning scrapped tires. The system includes a scrapped tire burner furnace, a heat exchanger for heating a cool heat transfer medium from the facility by the combustion gas from the furnace and supplying the heated medium to the facility, and an exhaust gas purifier for purifying sulfurous acid gas and carbon dust contained in exhaust gas. The purifier includes an exhaust gas tower having a vertical path to discharge the combustion gas, a water sprayer for spraying water from the upper side of the tower so that the sulfurous acid gas is made to melt to water and the carbon dust is made to adsorb to fall down, a neutralizer for precipitating sulfurous acid gas components into alkali salts in a sulfurous acid aqueous solution to thereby neutralize water, and a tank containing the solution and water.