The present disclosure provides an electroluminescent device and a method for preparing the same, a display panel and a display device. The electroluminescent device includes a light emitting layer, a cathode layer, and an electron transport layer arranged between the light emitting layer and the cathode layer. The electron transport layer includes at least a first electron transport material and a second electron transport material that have different LUMO energy levels, and a ratio EM1/EM2 of the weight content of the first electron transport material to that of the second electron transport material decreases in a direction from a surface thereof proximate to the cathode layer to a surface thereof proximate to the light emitting layer. The electroluminescent device of the present disclosure can improve its efficiency and lifetime.

An organic light-emitting diode (OLED) structure includes a stack of OLED layers that includes a light emission zone having a planar portion, and a light extraction layer formed of a UV-cured ink disposed over the light emission zone of the stack of OLED layers. The light extraction layer has a gradient in index of refraction along an axis normal to the planar portion.

A light-emitting device includes an anode, a cathode, and a crosslinked emissive layer disposed between the anode and the cathode in which quantum dots are dispersed. The crosslinked layer includes a crosslinked material and quantum dots dispersed in the crosslinked mater, the quantum dots having ligands respectively bonded to the quantum dots. The quantum dots are distributed unevenly within the crosslinked material. The ligands have a concentration relative to the weight of the quantum dots of 10 to 45 wt %. A method of forming a crosslinked emissive layer of a light-emitting device in which quantum dots are dispersed includes the steps of depositing a mixture on a deposition surface and subjecting at least a portion of the mixture to an activation stimulus to crosslink the cross-linkable material.

A light-emitting device includes an anode, cathode, and a combined charge transport and emissive layer (CCTEL) disposed on a deposition surface between the anode and cathode. The CCTEL includes a crosslinked charge transport material and quantum dots, the quantum dots distributed unevenly within the crosslinked charge transport material and arranged relative to the deposition layer. The quantum dots include nucleophilic or electrophilic centers and ligands respectively bonded to the quantum dots. The deposition surface has nucleophilic or electrophilic properties. A method of forming the CCTEL includes the steps of depositing a mixture on a deposition surface having nucleophilic or electrophilic properties. The mixture includes a solvent, cross-linkable charge transport material, and quantum dots comprising nucleophilic or electrophilic centers and ligands respectively bonded to the quantum dots. At least a portion of the mixture to an activation stimulus to crosslink the cross-linkable material.

A novel light-emitting device, a light-emitting device with high emission efficiency, a light-emitting device with a long lifetime, or a light-emitting device with low driving voltage is provided. An EL layer includes a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer in this order from the anode side. The first layer contains a first organic compound and a second organic compound. The fourth layer contains a seventh organic compound. The first organic compound exhibits an electron-accepting property with respect to the second organic compound. A HOMO level of the second organic compound is higher than or equal to −5.7 eV and lower than or equal to −5.4 eV. The fourth layer includes a region where the amount of seventh organic compound is large and a region where the amount of seventh organic compound is small in the thickness direction.

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.

A light-emitting device including a first electrode; a second electrode facing the first electrode; and interlayer arranged between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes a first emission layer and a second emission layer, the first emission layer includes a first dopant, wherein the second dopant is an electron-trapping dopant, and the second emission layer includes a third dopant and a fourth dopant, wherein the fourth dopant is a hole-trapping dopant.

A thin-film encapsulation structure, includes a number of inorganic film layers and at least one organic film layer laminated alternately at one side of an organic light-emitting diode. The number of inorganic film layers include N inorganic film layers including first to N-th inorganic film layers arranged sequentially from inside to outside, N≥2. At least the first inorganic film layer has a refractive index increasing gradually from inside to outside.

A light-emitting diode device and a manufacturing method therefor, and a display panel and a display apparatus. The light-emitting diode device comprises a quantum dot light-emitting layer, and a hole transport layer located at one side of the quantum dot light-emitting layer, wherein the hole transport layer comprises a perovskite material and an organic hole transport material. The high carrier mobility of a perovskite material can improve the carrier transport performance of a hole transport layer.

An organic light emitting display device is provided. The organic light emitting display device includes at least two or more light emitting parts between an anode and a cathode and each having a light emitting layer. At least one of the at least two or more light emitting parts includes an organic layer. The organic layer is formed of a compound comprising a functional group that reacts with alkali metals or alkali earth metals and a functional group with electron transport properties.