An organic electroluminescent device and a display apparatus. The organic electroluminescent device includes a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode, where the organic layer includes an emission layer (EML), the EML includes a host material, a thermally activated delayed fluorescence (TADF) sensitizer and a fluorescent dye, and the fluorescent dye is selected from a compound represented by Formula (1).

The present invention relates to the field of display technologies, and particularly to a fused polycyclic compound, a preparation method and use thereof. The fused polycyclic compound provided in the present invention has a structure of General Formula IV. The structure of the compound has ambipolarity, and the HOMO level and the LUMO level of the host material are respectively located on different electron donating group and electron withdrawing group, such that the transport of charges and holes in the host material becomes more balanced, thereby expanding the area where holes and electrons are recombined in the light emitting layer, reducing the exciton concentration, preventing the triplet-triplet annihilation of the device, and improving the efficiency of the device.

A compound of Formula I ##STR00001## wherein at least one of R.sup.1 or R.sup.2 includes a polycyclic group selected from the group consisting of Formula A, Formula B, and Formula C: ##STR00002##
wherein X.sup.1, X.sup.2, X.sup.3, and X.sup.4 are independently CR.sup.A or N; X.sup.5, X.sup.6, X.sup.7, and X.sup.8 are independently CR.sup.B or N; X.sup.9, X.sup.10, X.sup.11, and X.sup.12 are independently CR.sup.C or N; X.sup.13, X.sup.14, X.sup.15, and X.sup.16 are independently CR.sup.D or N; X.sup.17, X.sup.18, X.sup.19, and X.sup.20 are independently CR.sup.E or N; X.sup.21, X.sup.22, X.sup.23, and X.sup.24 are independently CR.sup.F or N; X.sup.25, X.sup.26, X.sup.27, and X.sup.28 are independently CR.sup.G or N; X.sup.29, X.sup.30, X.sup.31, and X.sup.32 are independently CR.sup.H or N; Y is selected from the group consisting of O, S, NR, and CRR′; the maximum number of N atoms that can connect to each other within each ring is two; with the proviso that R.sup.1 does not connect to ring B, and R.sup.2 does not connect to ring A, and wherein at least one of R.sup.C and R.sup.D of Formula A is a direct bond or an organic linker, one of R.sup.E and R.sup.F of Formula B is a direct bond or an organic linker, or one of R.sup.G, R.sup.H, and R.sup.N of Formula C is a direct bond or an organic linker.

A light emitting element includes a first electrode, a second electrode, and at least one functional layer which is disposed between the first electrode and the second electrode and includes a compound represented by Formula 1 below, thereby exhibiting high efficiency characteristics. The compound of Formula 1 may be included in the emission layer of the light emitting element as a dopant.

##STR00001##

A light emitting device includes a first electrode, a second electrode disposed on the first electrode, and at least one functional layer disposed between the first electrode and the second electrode. The at least one functional layer includes an amine compound represented by Formula 1. A light emitting device including the amine compound may show improved efficiency and life characteristics.

##STR00001##

An organic light-emitting device having low-driving voltage, improved efficiency, and long lifespan includes: a first electrode; a second electrode facing the first electrode; a first layer between the first electrode and the second electrode, the first layer including a first compound; a second layer between the first layer and the second electrode, the second layer including a second compound; and a third layer between the second layer and the second electrode, the third layer including a third compound; wherein the first compound does not include a nitrogen-containing heterocyclic group comprising *═N—*′ as a ring forming moiety, and wherein the first compound, the second compound, and the third compound each independently include at least one group selected from groups represented by Formulae A to C:

##STR00001##

Provided are an organic electronic element and an electronic device thereof, the organic electronic element being capable of achieving high light-emitting efficiency and a low driving voltage, and can also greatly improve the lifespan of the element by using a compound of the present invention as a phosphorescent host material.

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

Provided are a compound represented by Formula 1, an organic electroluminescent element comprising a first electrode, a second electrode, and an organic material layer formed between the first electrode and the second electrode, and electroluminescent device thereof, and by comprising the compound represented by Formula 1 in the organic material layer, the driving voltage of the organic electroluminescent element can be lowered, and the luminous efficiency and life time of the organic electroluminescent element can be improved.

Provided is a light-emitting device and an electronic apparatus including the same. 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 a capping layer, wherein the emission layer includes a first emitter, the first emitter emits a first light having a first emission spectrum, the capping layer is in a path along which the first light travels, an emission peak wavelength of the first light is about 520 nm to about 550 nm, the first emitter includes platinum, the capping layer includes an amine-containing compound, and a value of a ratio of CIEy to reflective index (RCR value) of the first light extracted to the outside through the capping layer is 38 or less, and the RCR value is calculated according to Equation 1.

CIEy/R(cap)×100  Equation 1