A light-emitting device with high heat resistance is provided. The light-emitting layer device includes an anode, a cathode; and an EL layer between the anode and the cathode. The EL layer includes a light-emitting layer and a first layer. The first layer is between the light-emitting layer and the cathode. The light-emitting layer is in contact with the first layer. The light-emitting layer includes a first organic compound and a light-emitting substance. The first layer includes a second organic compound. The light-emitting substance is a substance that emits blue light. The first organic compound is an organic compound including a fused aromatic hydrocarbon ring. The second organic compound is an organic compound including a heteroaromatic ring skeleton including one selected from a pyridine ring, a diazine ring, and a triazine ring; and a bicarbazole skeleton.

An organic electroluminescence device of an embodiment includes a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region, wherein the hole transport region includes a diamine compound represented by Formula 1, thereby showing high emission efficiency:

##STR00001##

An organic electroluminescent device is disclosed. The organic electroluminescent device includes a light-emitting layer that contains a plurality of hosts and dopants, where one of the plurality of hosts includes the same material as in an electron transport auxiliary layer in an electron transport region, whereby the organic electroluminescent device simultaneously exhibits effects such as low driving voltage, high luminous efficiency, and a long lifespan.

A light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode, wherein the interlayer includes an emission layer and an electron transport region, the electron transport region is between the emission layer and the second electrode, the electron transport region includes a first compound of Formula 1, an alkali metal halide, and a lanthanide metal, and the first compound includes one or more C.sub.8-C.sub.60 carbocyclic groups or a C.sub.8-C.sub.60 heterocyclic group, wherein, in Formula 1, the variables are defined herein.

A light-emitting device includes: a first electrode; a second electrode facing the first electrode; an interlayer between the first electrode and the second electrode and including an emission layer; and at least one fused cyclic compound of Formula 1:

##STR00001##

wherein the variables are described herein.

A composition comprising a compound represented by the following formula (1) and a compound represented by the following formula (2), provided that the compound represented by the formula (1) and the compound represented by the formula (2) are different compounds:

##STR00001##

Specific polycyclic compounds, a material for an organic electroluminescence device comprising said specific polycyclic compound, an organic electroluminescence device comprising said specific polycyclic compound, an electronic equipment comprising said organic electroluminescence device, a process for preparing said polycyclic compounds, and the use of said polycyclic compounds in an organic electroluminescence. (Formula I) (I)

##STR00001##

Disclosed are a light-emitting diode (LED) device, a manufacturing method thereof, and a display panel. The LED device includes a base substrate, a first electrode layer, an electron transport layer, a quantum dot light-emitting layer and a second electrode layer. The first electrode layer is laminated on the base substrate; the electron transport layer is laminated on a surface of the first electrode layer away from the base substrate; the quantum dot light-emitting layer is laminated on a surface of the electron transport layer away from the first electrode layer; the second electrode layer is laminated on the surface of the quantum dot light-emitting layer away from the electron transport layer; wherein the surface of the electron transport layer away from the first electrode layer is a first concave-convex surface including a plurality of protrusions.

A compound represented by the following formula (1A) or (1B):

##STR00001##

(the symbols in the formulae (1A) and (1B) have the same meaning as defined in the specification), an organic electroluminescent device containing the compound, and an electronic device including the organic electroluminescent device.

The present disclosure provides an organic electroluminescent device including: an anode; a cathode; and one or more organic material layers interposed between the anode and cathode and selected from the group consisting of a hole injection layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injection layer, and further including a lifetime enhancement layer (LEL) between the light emitting layer and the electron transporting layer.