Disclosed are nanostructures comprising Ag, In, Ga, and S and a shell comprising Ag, Ga and S, wherein the nanostructures have a peak wavelength emission of 480-545 nm and wherein at least about. 80% of the emission is band-edge emission. Also disclosed are methods of making the nanostructures.

Disclosed are a method for preparing a series of carbazole derivatives and use thereof in organic light-emitting diodes. The structure of the material is as shown in Formula I. An organic electroluminescent device prepared by the material can have a significantly improved power efficiency and an external quantum efficiency for the device and an extended life for an orange light or red light device; moreover, the material has characteristics, for example, methods for the synthesis and purification of the material are simple and suitable for large-scale production, and is an ideal choice as a luminescent material for organic electroluminescent devices. The use of the organic electroluminescent diode material as a carrier transport material or as a luminescent material alone or as a host material in a light-emitting layer also falls within the scope of protection.

##STR00001##

A quantum dot production method for producing quantum dots made of core particles and shells formed on outer surfaces of the core particles, the quantum dot production method includes: a preparing step of mixing a solution and a shell precursor together, in order to prepare a reaction solution, the solution containing a solvent and the core particles: a heating step of irradiating the core particles with light either in the solution or the reaction solution and generating heat, in order to heat surroundings of the core particles; and a shell forming step of causing reaction of the shell precursor on the outer surfaces of the core particles in the reaction solution, in order to form the shells on the outer surfaces of the core particles.

A composition that includes a fluorescent metal-organic framework (MOF) and a drilling fluid is provided. The MOF includes a porous, crystalline structure and a fluorescent source. A method includes introducing a MOF into a drilling fluid and circulating the drilling fluid through a well during a drilling operation that creates formation cuttings such that the fluorescent MOF interacts with the formation cuttings, creating tagged cuttings. The method further includes collecting returned cuttings from the circulating drilling fluid at a surface of the well, detecting the presence of the fluorescent MOF on the returned cuttings to identify the tagged cuttings, and correlating the tagged cuttings with a drill depth in the well at a time during the drilling operation.

Metal complexes containing heteroaryl and its analogues as ligands are disclosed in this application. These compounds may be useful as charge transport materials in OLEDs.

A novel light-emitting element is provided. A light-emitting element with high emission efficiency is provided. A light-emitting element with high color purity is provided. The light-emitting element includes an anode, a cathode, and a layer including the light-emitting substance between the anode and the cathode. The layer including the light-emitting substance includes a light-emitting layer, a first electron-transport layer, and a second electron-transport layer. The light-emitting layer and the first electron-transport layer are in contact with each other. The first electron-transport layer and the second electron-transport layer are in contact with each other. The first electron-transport layer and the second electron-transport layer are positioned between the light-emitting layer and the cathode. The light-emitting layer includes a metal-halide perovskite material represented by General Formula (SA)MX.sub.3, General Formula (LA).sub.2(SA).sub.n-1M.sub.nX.sub.3n+1, or General Formula (PA)(SA).sub.n-1M.sub.nX.sub.3n+1. The first electron-transport layer includes a first electron-transport material, and the second electron-transport layer includes a second electron-transport material.

Complexes and devices, such as organic light emitting devices and full color displays, including a compound of the formula:

##STR00001## wherein: M is Pd.sup.2+, Ir.sup.+, Rh.sup.+, or Au.sup.3+; each of V.sup.1, V.sup.2, V.sup.3, and V.sup.4 is coordinated to M and is independently N, C, P, B, or Si; each of L.sup.1, L.sup.2, L.sup.3, and L.sup.4 is independently a substituted or unsubstituted aryl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, carbene, or N-heterocyclic carbene; and Z is O, S, NR, CR.sub.2, SiR.sub.2, BR, PR,

##STR00002## where each R is independently substituted or unsubstituted C.sub.1-C.sub.4 alkyl or substituted or unsubstituted aryl.

Use of transition metal complexes of the formula (I) in organic light-emitting diodes

##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or 1; o is the number of ligands K, where o can be 0 or 1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also
an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising at least two carbene ligands.

Disclosed are a core-shell quantum dot, a quantum dot light-emitting device, a display apparatus and a manufacturing method. The core-shell quantum dot includes: a core part; a shell layer arranged on at least part of a surface of the core part, and including metal ions; and a chelating ligand connected with the metal ions, where the chelating ligand and the metal ions form a closed ring structure connected with the shell layer.

Disclosed is a long-afterglow luminescent material, comprising A) at least one light-absorbing agent, B) at least one luminescent agent, and C) at least one photochemical cache agent. The light-absorbing agent and the luminescent agent are compounds having different structures, and the cache agent is selected from one or more compounds of formula (I), (II) and/or (III). ##STR00001## The material has luminescent intensity reaching the level of commercialized inorganic long-afterglow powder SrAl.sub.2O.sub.4:Eu.sup.2+, Dy.sup.3+, and can emit light when the exciting light is turned off with a light emitting time up to 100 ms to 3600 s.