An organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and comprising a fluorescent emission layer. The fluorescent emission layer includes a first host (H1), a second host (H2), a first dopant (D1), and a second dopant (D2).

Provided are a polycyclic compound represented by Formula 1 and an organic light-emitting device and an electronic apparatus, each including the same.

An organic electroluminescence device includes: an anode; an emitting layer; and a cathode, the emitting layer containing a first material, a second material and a third material, the first material being a fluorescent material, the second material being a delayed fluorescent material, the third material having a singlet energy larger than a singlet energy of the second material.

An organic light-emitting device including a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer includes an emission layer, the emission layer includes a host, a dopant, and a sensitizer, the host does not include a metal atom, the dopant emits light, and the light has a decay time of about 100 nanoseconds or less, and the sensitizer includes an organometallic compound represented by one selected from Formulae 1 and 2 described in the specification.

Provided are a condensed cyclic compound represented by Formula 1-1 or 1-2, an organic light-emitting device including the condensed cyclic compound, and an electronic apparatus including the organic light-emitting device:

##STR00001## wherein Formulae 1-1 and 1-2 are the same as described in the present specification.

Disclosed are an organic light-emitting device and an electronic apparatus including the same. The organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer located between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes a host compound, a first dopant compound, and a second dopant compound, and the second dopant compound is represented by Formula 1,

A-(Ar.sub.1).sub.n11  Formula 1

wherein, in Formula 1, A is a group represented by Formula 1-1,

##STR00001##

wherein, in Formulae 1 and 1-1, Ar.sub.1, n11, M, CY.sub.1 to CY.sub.5, R.sub.1 to R.sub.5, and a1 to a5 are the same as described in the specification.

A light emitting element includes a first electrode, a second electrode disposed on the first electrode, and an emission layer disposed between the first electrode and the second electrode. The emission layer may include a hole transporting host, an electron transporting host, a phosphorescent sensitizer, and a delayed fluorescent dopant. The delayed fluorescent dopant may have a greater absolute value of the HOMO energy level than the hole transporting host. Accordingly, the light emitting element including the delayed fluorescent dopant in an embodiment may exhibit long lifespan.

An organic electroluminescence device and a display apparatus, where the organic electroluminescence device includes an organic light emitting layer which includes a host material, a sensitizer material, and a resonance thermally activated delayed fluorescent material, where the host material is a wide bandgap material, and the sensitizer material is an exciplex material, a singlet state energy level for the wide bandgap material is greater than a singlet state energy level for the exciplex, and a triplet state energy level for the wide bandgap material is greater than a triplet state energy level for the exciplex, and a singlet state energy level for the exciplex material is greater than a singlet state energy level for the resonance delayed fluorescent material, and a triplet state energy level for the exciplex material is greater than a triplet state energy level for the resonance delayed fluorescent material.

A light-emitting element having high emission efficiency is provided. The light-emitting element includes a first organic compound, a second organic compound, and a third organic compound. The first organic compound has a function of converting triplet excitation energy into light emission. The second organic compound is preferably a TADF material. The third organic compound is a fluorescent compound. Light emitted from the light-emitting element is obtained from the third organic compound. Triplet excitation energy in a light-emitting layer is transferred to the third organic compound by reverse intersystem crossing caused by the second organic compound or through the first organic compound.

An embodiment of the present disclosure provides an organic light emitting diode comprising a first electrode; a second electrode facing the first electrode; and a first emitting material layer including a first delayed fluorescent dopant and a first phosphorescent dopant and disposed between the first and second electrodes, wherein a percentage by weight of the first phosphorescent dopant with respect to the first delayed fluorescent dopant is equal to or less than 5.