A light emitting element (e.g., light emitting diode) includes a first electrode, a hole transport region on the first electrode, an emission layer on the hole transport region and containing a quantum dot complex, an electron transport region on the emission layer, and a second electrode on the electron transport region, wherein the quantum dot complex contains two or more quantum dots each including a core and a shell surrounding the core, the shell of one quantum dot is combined with a shell of at least one neighboring quantum dot, and the light emitting element (e.g., light emitting diode) may thus have improved luminous efficiency and service life.

The present disclosure provides a light emitting device including: a first electrode; a first light emitting layer on a side of the first electrode; an N-type charge generation layer on a side of the first light emitting layer distal to the first electrode; a P-type charge generation layer on a side of the N-type charge generation layer distal to the first light emitting layer; a second light emitting layer on a side of the P-type charge generation layer distal to the N-type charge generation layer; and a second electrode on a side of the second light emitting layer distal to the P-type charge generation layer. The N-type charge generation layer includes a host material which has a lowest unoccupied molecular orbital energy level less than or equal to −2.9 and a glass transition temperature greater than 130° C.

The present application provides an organic electroluminescent device and a manufacturing method thereof. A host material of a light-emitting layer of the organic electroluminescent device is co-evaporated by a donor host material and a acceptor host material in a same evaporation source to form an exciplex, which solves the technical problems such as low luminous efficiency, short service life or complicated operation process of the organic electroluminescent device in the prior art. The organic electroluminescent device according to the present application includes an anode, a cathode and a light-emitting layer disposed between the anode and the cathode, a host material of the light-emitting layer is formed by premixing a donor host material and a acceptor host material, the donor host material and the acceptor host material are co-evaporated in a same evaporation source to form an exciplex, and the host material is doped with a guest material.

A composition for a light-emitting element contains a host material and a guest material. The host material is a compound containing at least one of an aromatic hydrocarbon group and a heterocyclic group and the guest material is a compound having a condensed heterocyclic group containing at least one of a boron atom, an oxygen atom, a sulfur atom, a selenium atom, an sp.sup.3 carbon atom, and a nitrogen atom in a ring. A difference ΔE between an energy value at the maximum peak of a emission spectrum of the host material at 25° C. and an energy value at a peak on the lowest energy side of an absorption spectrum of the guest material at 25° C. is 0.50 eV or less, and a difference ΔS between an energy value at the maximum peak of an emission spectrum of the guest material at 25° C. and an energy value at the maximum peak of an emission spectrum of the guest material at 77 K is 0.10 eV or less.

A phase-transition optical isomer compound is described, a transparent EL display device including the phase-transition optical isomer compound and a method of fabricating the EL display device, where a phase of the phase-transition optical isomer compound is transited by light irradiation and a second electrode of the EL display device is selectively deposited without a masking process.

A display device includes a display panel that is bent with respect to a bending area. A coating layer is disposed below the display panel and may include a resin. A portion of the coating layer, which is adjacent to the bending area, may have a thickness that gradually decreases in a direction toward the bending area.

A display panel and a display device are provided. The display panel includes a flexible screen body having a first region and a second region. The second region has a bending transitional region coplanar with the first region, a bending region, and an extending region connected in sequence. The first region is connected to the bending region through the bending transitional region and is at least a part of an active region. The bending region and the extending region are at least a part of a non-active region and not coplanar with the first region. The bending transitional region is another part of the active region or another part of the non-active region. The display panel further includes a buffer layer disposed on surfaces of the bending transitional region and the bending region at a stress concentration side thereof. At least two sections of the buffer layer have different hardnesses.

The present invention relates to OLED devices and stacks for OLED devices that include a symmetric emissive-layer architecture. In one embodiment, the present invention relates to an emissive stack having three layers, wherein the top and bottom layers emit light in the same or similar color region while the middle layer emits light in a different color region than the other two layers. In such an embodiment, the three layers are in contact with each other with no other layers in between. The symmetric emissive-layer architecture of the present invention can be used to improve the color stability of OLED devices.

Disclosed are an organic light emitting display device and lighting apparatus for vehicles using the same. The organic light emitting display device includes a first layer including a first organic layer and a first emission layer on a first electrode, a second layer including a second emission layer and a second organic layer on the first layer, a second electrode on the second layer, and a third organic layer between the first layer and the second layer. A thickness of the first emission layer is equal to or greater than a thickness of each of the first organic layer and the second organic layer.

A manufacturing method for a functional film provided on an upper surface of a long substrate, includes coating an ink containing a material of the functional film on the upper surface of the substrate to form a coating film, and drying the coating film while conveying the substrate. The drying process includes a first process in which the substrate is conveyed for a first distance and a temperature of the substrate is raised from a first temperature to a second temperature during conveyance. In the first process, assuming that the first distance is d.sub.1 (m), the first temperature is T.sub.1 (° C.), and the second temperature is T.sub.2 (° C.), the following expression is satisfied: (T.sub.2−T.sub.1)/d.sub.1≥10 (1a). A maximum value of an instantaneous temperature change rate of the substrate is 5° C./sec or less.