We disclose herein a hetero-structure comprising: a curved material; at least one layer of a first material rolled around the curved material; at least one intermediate layer rolled on the at least one layer of the first material; and at least one layer of a second material rolled around the at least one intermediate layer.

The invention relates to an optoelectronic material comprising a compound, wherein the compound comprises: (i) one or more cations, A; (ii) one or more first B cations, B.sup.n+; (iii) one or more second B cations, B.sup.m+; and (iv) one or more chalcogen anions, X; wherein the one or more first B cations, B.sup.n+ are different from the one or more second B cations, B.sup.m+; n represents the oxidation state of the first B cation and is a positive integer of from 1 to 7 inclusive; m represents the oxidation state of the second B cation and is a positive integer of from 1 to 7 inclusive; and n+m is equal to 8.

A method of fabricating a perovskite light emitting device is provided. In one embodiment, the method comprises the steps of: providing a substrate; providing a first electrode disposed over the substrate; providing a bank structure disposed over the substrate, wherein the bank structure is patterned so as to define at least one sub-pixel on the substrate; providing a first transport layer ink, wherein the first transport layer ink comprises at least one solvent and at least one first charge transport material mixed in the at least one solvent; depositing the first transport layer ink into the at least one sub-pixel over the first electrode using a method of inkjet printing; vacuum drying the first transport layer ink inside a vacuum drying chamber to assemble a first transport layer over the first electrode in the at least one sub-pixel; annealing the first transport layer; providing a perovskite ink, wherein the perovskite ink comprises at least one solvent and at least one perovskite light emitting material mixed in the at least one solvent; depositing the perovskite ink into the at least one sub-pixel over the first transport layer using a method of inkjet printing; vacuum drying the perovskite ink inside a vacuum drying chamber to assemble a perovskite emissive layer over the first transport layer in the at least one sub-pixel; annealing the perovskite emissive layer; and depositing a second electrode over the perovskite emissive layer using a method of vapour deposition. Perovskite light emitting devices and displays fabricated using the provided method are also provided.

A method of fabricating a perovskite light emitting device is provided. In one embodiment, the method comprises the steps of: providing a substrate; providing a first electrode disposed over the substrate; providing a bank structure disposed over the substrate, wherein the bank structure is patterned so as to define at least one sub-pixel on the substrate; providing a first transport layer ink, wherein the first transport layer ink comprises at least one solvent and at least one first charge transport material mixed in the at least one solvent; depositing the first transport layer ink into the at least one sub-pixel over the first electrode using a method of inkjet printing; vacuum drying the first transport layer ink inside a vacuum drying chamber to assemble a first transport layer over the first electrode in the at least one sub-pixel; annealing the first transport layer; providing a perovskite ink, wherein the perovskite ink comprises at least one solvent and at least one perovskite light emitting material mixed in the at least one solvent; depositing the perovskite ink into the at least one sub-pixel over the first transport layer using a method of inkjet printing; vacuum drying the perovskite ink inside a vacuum drying chamber to assemble a perovskite emissive layer over the first transport layer in the at least one sub-pixel; annealing the perovskite emissive layer; and depositing a second electrode over the perovskite emissive layer using a method of vapour deposition. Perovskite light emitting devices and displays fabricated using the provided method are also provided.

A halide material having general formula ArMAX is disclosed. The halide material can be processed to an optoelectronic film with a halogenated formamidine and a lead halide, and the optoelectronic film can be applied in the manufacture of an optoelectronic device like a perovskite laser or a PeLED. Experimental data have proved that, the fabricated optoelectronic film shows a property of photoluminescence (PL) peak wavelength adjustable. Moreover, the PL peak wavelength moves from 482 nm to 534 nm with the increase of the content of lead (Pb), halogen (X) and formamidine (FA) in the optoelectronic film. Furthermore, experimental data have also indicated that, the fabricated optoelectronic film can be used as a blue emissive layer, a red emissive layer or a green emissive layer, thereby having a significant potential for application in optoelectronics industry.

Provided are a method for manufacturing a perovskite nanocrystal particle light-emitter where an organic ligand is substituted, a light-emitter manufactured thereby, and a light emitting device using the same. A method for manufacturing an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter where an organic ligand is substituted may comprise the steps of: preparing a solution including an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, wherein the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter comprises an organic-inorganic-hybrid perovskite nanocrystal structure and a plurality of first organic ligands surrounding the organic-inorganic-hybrid perovskite nanocrystal structure; and adding, to the solution, a second organic ligand which is shorter than the first organic ligands or includes a phenyl group or a fluorine group, thereby substitutes the first organic ligands with the second organic ligand. Thus, since energy transfer or charge injection into the nanocrystal structure increases through ligand substitution, it is possible to further increase light emitting efficiency and increase durability and stability by means of a hydrophobic ligand.

Methods and devices for forming painted circuits using multiple layers of electrically conductive paint. In one aspect, a painted circuit includes a substrate (111) and one or more paint layer (106, 108, 110, 112, 114, 116, 120, 122) applied to the substrate, where the one or more paint layers each form an electrical component of the painted circuit. A given paint layer of the one or more paint layers includes a conductive paint formulation having a resistance that is defined by a concentration of conductive material that is included in the conductive paint formulation and a thickness of the given paint layer, and lower concentrations of the conductive material included in the conductive paint formulation provide a higher resistance than higher concentrations of conductive material.

The present disclosure relates to a composition that includes a first layer that includes a perovskite defined by ABX.sub.3 and a second layer that includes a perovskite-like material defined by at least one of A′.sub.2B′X′.sub.4, A′.sub.3B′.sub.2X′.sub.9, A′B′X′.sub.4, A′.sub.2B′X′.sub.6, and/or A′.sub.2AB′.sub.2X′.sub.7, where the first layer is adjacent to the second layer, A is a first cation, B is a second cation, X is a first anion, A′ is a third cation, B′ is a fourth cation, X′ is a second anion, and A′ is different than A.

The present disclosure relates to a composition that includes a first layer that includes a perovskite defined by ABX.sub.3 and a second layer that includes a perovskite-like material defined by at least one of A′.sub.2B′X′.sub.4, A′.sub.3B′.sub.2X′.sub.9, A′B′X′.sub.4, A′.sub.2B′X′.sub.6, and/or A′.sub.2AB′.sub.2X′.sub.7, where the first layer is adjacent to the second layer, A is a first cation, B is a second cation, X is a first anion, A′ is a third cation, B′ is a fourth cation, X′ is a second anion, and A′ is different than A.

A method of preparing a film and a light-emitting device are disclosed. The method includes: providing at least one gas-phase source above a substrate, the at least one gas-phase source made of materials comprising a perovskite material; and controlling an evaporation rate of the at least one gas-phase source to form a perovskite film. In the method provided by the present invention, a perovskite light-emitting layer is prepared by gas-phase source evaporation coating without an organic solvent, which avoids miscibility between the organic solvent and other layers and improves compatibility between the perovskite material and other film materials, thereby realizing the low preparation cost and the simple preparation process.