The present invention relates to an organic light emitting diode comprising a substrate, an anode, a cathode, an emission layer, an electron injection layer and an electron transport layer stack; and to a display device or lighting device comprising the same.

A novel light-emitting device that is highly convenient, useful, or reliable is provided. The light-emitting device includes a first electrode, a second electrode, and a first unit. The first unit is located between the first electrode and the second electrode, and the first unit has a function of emitting light. The first unit contains a light-emitting organic compound and an organic compound HRM. The organic compound HRM has four or more rotatable bonds and a principal moment of inertia. The principal moment of inertia includes a first normalized principal moment of inertia NPR1 and a second normalized principal moment of inertia NPR2 in a predetermined region.

An organic light-emitting device includes a first electrode, a second electrode facing the first electrode, an emission layer between the first electrode and the second electrode, and a hole transport region between the first electrode and the emission layer. The emission layer includes a first compound represented by Formula 1, and the hole transport region includes a second compound represented by Formula 2: ##STR00001##

The present invention relates to a compound of formula (I) and an organic electronic device comprising a semiconductor layer which comprises a compound of formula (I).

An organic electroluminescence element including an anode, a light-emitting layer, a functional layer, and a cathode stacked in this order. The light-emitting layer and the functional layer are in contact with each other. Hole mobility of the light-emitting layer is greater than electron mobility of the light-emitting layer. The electron mobility of the light-emitting layer is equal to or greater than an effective electron mobility of the functional layer. A highest occupied molecular orbital (HOMO) level of a first functional material included in the light-emitting layer is at least 0.4 eV greater than a HOMO level of a second functional material included in the functional layer.

A compound represented by the following formula (1) (L.sub.1 is a single bond or an unsubstituted arylene group having 6 to 50 ring carbon atoms, and Ar.sub.1 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms).

##STR00001##

A light-emitting device having an electron transport layer that includes a first electron transport layer including an inorganic oxide and a second electron transport layer including an organic material is provided. The first electrode is a reflective electrode.

A light-emitting device includes an electron transport region including a first electron transport layer and a second electron transport layer. The first electron transport layer includes a first compound, the second electron transport layer includes a second compound, the first compound includes a pyrimidine group, the second compound includes a triazine group, and an absolute value of a lowest unoccupied molecular orbital (LUMO) energy of the first compound (E.sub.LUMO_E1) is less than an absolute value of a LUMO energy of the second compound (E.sub.LUMO_E2). An electronic apparatus including the light-emitting device.

Organic electroluminescent devices with lowered driving voltages, and enhanced efficiencies and lifetimes are provided.

A display panel and a method of manufacturing thereof are provided. A hole injection layer, a hole transport layer, a light emitting layer, and a planarization layer are formed by an inkjet-printing method. Specifically, solvents including hole injecting layer material, hole transporting layer material, light emitting layer material, and planarization layer material are evaporated by vacuum drying so as to uniformize the surface of the entire layer, thereby improving light uniformity. Moreover, a notch of the light emitting layer can be effectively filled by disposing a planarization layer on the light emitting layer, so a uniform layer can be formed, which can reduce the current accumulated at the notch. Therefore, the light uniformity of the display panel is improved, and the risk of leakage current at the notch is also reduced.