A technique is provided that improves the efficiency of electron and hole injection in a light-emitting element containing quantum dots in a light-emitting layer thereof and hence improves the luminous efficiency thereof The light-emitting element includes on a substrate: a positive electrode; a negative electrode; a quantum-dot layer between the positive electrode and the negative electrode, the quantum-dot layer including a stack of a plurality of luminous, first quantum dots and a plurality of non-luminous, second quantum dots; a hole transport layer between the positive electrode and the quantum-dot layer; and an electron transport layer between the negative electrode and the quantum-dot layer, the plurality of second quantum dots being more numerous in an electron transport layer side than in a hole transport layer side.

Disclosed are a quantum dot light emitting device and a manufacturing method thereof as well as a display apparatus. The quantum dot light emitting device includes: a substrate; a pixel definition layer, wherein the pixel definition layer includes a plurality of pixel openings and pixel partition bodies, and a surface of each pixel partition body has a hydroxide radical; a quantum dot layer, located in the pixel openings; and a polymer structure sealing the quantum dot layer in the pixel openings, wherein the polymer structure is a of fully enclosed structure at least formed by polymerization of siloxane, thiol siloxane and the hydroxide radical, the siloxane, the hydroxide radical and the thiol siloxane are all polymerized, and a sulfur atom of a thiol in the thiol siloxane is combined with a coordinating atom of the quantum dot layer.

The present invention provides an organic electroluminescent diode device, a display panel, and a manufacturing method thereof. The organic electroluminescent diode device includes a first electrode layer, a conductive layer, an electron injection layer, a light-emitting layer, a hole injection layer, and a second electrode layer, and the conductive layer is provided between the first electrode layer and the electron injection layer.

A compound including a first ligand L.sub.A of Formula I,

##STR00001##

is disclosed. In Formula I, ring B is a 5- or 6-membered ring; X.sup.1, X.sup.2, and X.sup.3 are each CR.sub.A or N; R is a 5- or 6-membered carbocyclic or heterocyclic ring, which can be further fused or substituted; and (1) when ring B is an unfused 6-membered ring, X.sup.1 and X.sup.2 are N, and X.sup.3 is C; and (2) when ring B is a fused 6-membered ring, ring B has the structure of Formula II,

##STR00002##

In this structure, the wavy line indicates the point of connection to ring A; Q.sup.1 to Q.sup.6 are each C or N; and, when proviso (2) applies, (I) at least one of X.sup.1, X.sup.2, and X.sup.3 is N; or (II) R is two or more fused or unfused 5- or 6-membered carbocyclic or heterocyclic rings, or (III) at least ring A or R is substituted with a partially or fully deuterated alkyl or partially or fully deuterated cycloalkyl group.

Provided are organometallic compounds including a ligand L.sub.A having a structure of

##STR00001##

Also provided are formulations comprising these organometallic compounds. Further provided are OLEDs and related consumer products that utilize these organometallic compounds.

Provided are Platinum and Iridium complexes with spiro[4.4]nonane and analogs-including ligands. Also provided are formulations including these Platinum and Iridium complexes with spiro[4.4]nonane and analogs-including ligands. Further provided are OLEDs and related consumer products that utilize these Platinum and Iridium complexes with spiro[4.4]nonane and analogs-including ligands.

A quantum dot (QD) composite material includes at least three QD structural units arranged sequentially along a radial direction. Among the at least three QD structural units, each QD structural unit at a center of the QD composite material and each QD structural unit at a surface of the QD composite material have a gradient alloy composition structure with an energy level width increasing along the radial direction from the center to the surface, along the radial direction, energy levels of adjacent gradient alloy composition structures of the QD structure units are continuous. A QD structural unit located between the QD structural units at the center and the QD structural units at the surface have a homogeneous alloy composition structure.

A quantum dot (QD) composite material includes at least two structural units arranged sequentially along a radial direction. The at least two structural units include a type A1 structural unit and a type A2 structural unit. The type A1 QD structural unit has a gradient alloy composition structure with an energy level width increasing along the radial direction toward a surface, and the type A2 QD structural unit has a gradient alloy composition structure with the energy level width decreasing along the radial direction toward the surface. The two types of QD structural units are arranged alternately along the radial direction, and the energy levels in adjacent QD structural units having gradient alloy composition structures are continuous.

A quantum dot (QD) composite material includes at least two structural units arranged sequentially along a radial direction. The QD composite material includes a type A3 QD structural unit and a type A4 QD structural unit. The type A3 QD structural units has a gradient alloy composition structure with an energy level width increasing along the radial direction toward a surface, and the type A4 QD structural unit has a homogeneous alloy composition structure. An inner part of the QD composite material includes one or more QD structural units having a gradient alloy composition structure, and energy levels in adjacent QD structural units having gradient alloy composition structures are continuous. The QD composite material includes one or more QD structural units having a homogeneous alloy composition structure in a region close to the surface.

The present application discloses a first aspect provides a quantum dot light-emitting diode, including: a cathode and an anode which are oppositely arranged; a quantum dot light-emitting layer arranged between the cathode and the anode; and a stacked layer arranged between the cathode and the quantum dot light-emitting layer. A stacked layer includes: a first metal oxide nanoparticle layer, and a mixed material layer arranged on a surface of the first metal oxide nanoparticle layer far away from the quantum dot light-emitting layer. The mixed material layer includes: first metal oxide nanoparticles, and a second metal oxide dispersed among gaps of the first metal oxide nanoparticles. First metal oxide nanoparticles in the first metal oxide nanoparticle layer serve as an electron transport material. A content of the second metal oxide in the mixed material layer gradually increases in a direction from the quantum dot light-emitting layer to the cathode.