The present disclosure relates to compounds capable of emitting delayed fluorescence, and uses of the compounds in organic light-emitting diodes.

A light-emitting device includes a first light-emitting layer and a second light-emitting layer that are stacked. A material of the first light-emitting layer includes a first host material and a first TADF sensitizer. A material of the second light-emitting layer includes a second host material, a second TADF sensitizer, and a second fluorescent emissive material. Transmission rates of the material of the first light-emitting layer and the material of the second light-emitting layer to holes are greater than transmission rates of the material of the first light-emitting layer and the material of the second light-emitting layer to electrons, and there is a first overlapping region between a normalized electroluminescence spectrum of the first TADF sensitizer and a normalized absorption spectrum of the second fluorescent emissive material.

Disclosed are an organic light emitting device and a display device using the same in which a light emitting layer includes a host and a plurality of dopants. In the light emitting layer, energy is transferred from a host and other dopants to one dopant by energy transfer system, thus it is possible to increase luminous efficacy of a single color and to increase lifetime of emission.

A light emitting device according to an embodiment includes a first electrode and a second electrode facing the first electrode, and a plurality of organic layers between the first electrode and the second electrode, wherein at least one among the plurality of organic layers includes a fused polycyclic compound represented by Formula 1 below, thereby showing improved emission efficiency. ##STR00001##

A light-emitting device including a heterocyclic compound represented by Formula 1 and a phosphorescent dopant, and an electronic apparatus including the light-emitting device are provided. Formula 1 is the same as described in the present specification. The 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 the heterocyclic compound represented by Formula 1 ##STR00001##

A light-emitting device includes a first compound represented by Formula 1; and a second compound, a third compound, a fourth compound, or any combination thereof, each having a specific formula: ##STR00001##
emitting device may have excellent driving voltage, current density, high luminescence efficiency, and long lifespan, and may be used in the manufacture of a high quality electronic apparatus.

The present disclosure provides a delayed fluorescent compound of following Formula, and an organic light emitting diode including a first electrode, a second electrode and an organic emitting layer between the first and second electrodes, where the delayed fluorescent compound is included in the organic emitting layer, and an organic light emitting display device including the organic emitting compound. ##STR00001##

Provided is an organic electroluminescence device including an emission layer between a first electrode and a second electrode, wherein the emission layer includes a first host represented by Formula 1, a second host which is different from the first host, a first dopant which is a thermally activated delayed fluorescence material having an electron donor and an electron acceptor, and a second dopant represented by Formula 2. ##STR00001##

The present disclosure relates to an organic light emitting diode and an organic light emitting device having the diode. An organic light emitting diode including a plurality of delayed fluorescent materials with specific energy levels and an organic light emitting device including the diode is disclosed. When the plurality of delayed fluorescent materials with specific energy levels are applied in an emitting material layer, it is possible to minimize the energy loss or exciton quenching during luminescent process, to prevent the diode from reducing lifetime caused by the exciton quenching, and to make charges being injected into the emitting material layer in balance. When the emitting material layer includes other luminous material having a narrow FWHM, the organic light emitting diode can enhance its color purity.

The present invention relates to compounds of the formula (1) which are suitable for use in electronic devices, in particular organic electroluminescent devices, and to electronic devices which comprise these compounds.