A compound containing Sn, Te and Mg, and further containing either one or both of Sb and Bi.

A cadmium free quantum dot or a population thereof or a device including the same, wherein the cadmium free quantum dot includes a core (or a semiconductor nanocrystal particle) including a first semiconductor including a Group IIB-VI compound and a shell (or a coating) disposed on the core (or the semiconductor nanocrystal particle) including a Group IIB-V compound and exhibits a quantum efficiency of about 60% or higher.

A cadmium free quantum dot or a population thereof or a device including the same, wherein the cadmium free quantum dot includes a core (or a semiconductor nanocrystal particle) including a first semiconductor including a Group IIB-VI compound and a shell (or a coating) disposed on the core (or the semiconductor nanocrystal particle) including a Group IIB-V compound and exhibits a quantum efficiency of about 60% or higher.

The present disclosure relates to a core-shell type quantum dot, comprising a quantum dot core, a light-transmitting inorganic mesoporous material layer on a surface of the quantum dot core, and a filler different from the inorganic mesoporous material in mesopores of the light-transmitting inorganic mesoporous material layer. The present disclosure also relates to the preparation and use of the core-shell type quantum dot core. The quantum dot core is coated with the light-transmitting inorganic mesoporous material and the mesopores of the inorganic mesoporous material are filled with the filler different from the inorganic mesoporous material, and the core-shell type quantum dots thus obtained not only have improved optical stability and chemical stability, but also have adjustable optical properties.

The present disclosure relates to a core-shell type quantum dot, comprising a quantum dot core, a light-transmitting inorganic mesoporous material layer on a surface of the quantum dot core, and a filler different from the inorganic mesoporous material in mesopores of the light-transmitting inorganic mesoporous material layer. The present disclosure also relates to the preparation and use of the core-shell type quantum dot core. The quantum dot core is coated with the light-transmitting inorganic mesoporous material and the mesopores of the inorganic mesoporous material are filled with the filler different from the inorganic mesoporous material, and the core-shell type quantum dots thus obtained not only have improved optical stability and chemical stability, but also have adjustable optical properties.

Provided are a quantum dot, a method of preparing the quantum dot, an optical member including the quantum dot, and an electronic device including the quantum dot. The quantum dot includes a core including indium (In), A.sup.1, and A.sup.2; and a shell covering the core. A.sup.1 is a Group V element, A.sup.2 is a Group III element other than indium, and the core includes a first region, and a second region covering the first region. The first region does not include A.sup.2, and includes indium and A.sup.1, and the second region includes indium, A.sup.1, and A.sup.2, and indium and A.sup.2 are alloyed with each other in the second region.

Provided are a quantum dot, a method of preparing the quantum dot, an optical member including the quantum dot, and an electronic device including the quantum dot. The quantum dot includes a core including indium (In), A.sup.1, and A.sup.2; and a shell covering the core. A.sup.1 is a Group V element, A.sup.2 is a Group III element other than indium, and the core includes a first region, and a second region covering the first region. The first region does not include A.sup.2, and includes indium and A.sup.1, and the second region includes indium, A.sup.1, and A.sup.2, and indium and A.sup.2 are alloyed with each other in the second region.

A supercapacitor electrode comprises a mixture of graphene sheets and humic acid. The humic acid occupies 0.1% to 99% by weight of the mixture and the graphene sheets are selected from a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.001% to 5% by weight of non-carbon elements. The non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, or a combination thereof. The mixture has a specific surface area greater than 500 m.sup.2/g.

A supercapacitor electrode comprises a mixture of graphene sheets and humic acid. The humic acid occupies 0.1% to 99% by weight of the mixture and the graphene sheets are selected from a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.001% to 5% by weight of non-carbon elements. The non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, or a combination thereof. The mixture has a specific surface area greater than 500 m.sup.2/g.

A thermoelectric conversion material is represented by a composition formula Ag.sub.2S.sub.(1-x)Se.sub.x, where x has a value of greater than 0.01 and smaller than 0.6.