Abstract: The present disclosure discloses an organic electroluminescent device and a preparation method thereof. The device includes a light-emitting layer, the light-emitting layer includes a host material, an auxiliary host material and a fluorescent dye; the host material is an exciplex prepared by mixing an electron donor material and an electron acceptor material, the auxiliary host material is a thermally activated delayed fluorescence material, a singlet energy level and a triplet energy level of the exciplex are higher than the single energy level and triplet energy level of the auxiliary host material. The above organic electroluminescent device can promote the reverse intersystem crossing of the host material and the auxiliary host material from the triplet excitons to the singlet excitons, enhance the Foster energy transfer, reduce the triplet exciton quenching, therefore the efficiency roll-off of the device is small and the external quantum efficiency is high.

Abstract: The present disclosure relates to display technologies, and particularly discloses an organic electroluminescent device. This organic electroluminescent device includes a light-emitting layer, the light-emitting includes an exciplex composed of a donor molecule and an acceptor molecule, and a wide band gap material for increasing the inter-molecular spacing between the donor molecule and the acceptor molecule. According to the device of the present disclosure, the degree of orbital overlap of HOMO and LUMO of the formed exciplex and the singlet-triplet energy level difference can be reduced, the reverse intersystem crossing rate (kRISC) of the exciplex host can be increased, the Föster energy transferred to the guest molecule can be enhanced, and the efficiency and the lifetime of the device can be improved.

Abstract: 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.

Abstract: An organic electroluminescence device, a preparation method thereof, and a display apparatus, the organic electroluminescence device including 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 a thermally activated delayed fluorescent material. The singlet state energy level of the thermally activated delayed fluorescent material falls between the singlet state energy level of the wide bandgap material and the singlet state energy level of the resonance thermally activated delayed fluorescent material. The triplet state energy level of the thermally activated delayed fluorescent material falls between the triplet state energy level of the wide bandgap material and the triplet state energy level of the resonance thermally activated delayed fluorescent material.

Abstract: The present disclosure relates to the technical field of display, and specifically relates to an organic electroluminescent device, and in particular, to a highly efficient fluorescence device. An organic electroluminescent device includes a hole transport layer, and a light-emitting layer. The hole transport layer and the light-emitting layer has an interface exciplex formed at an interface therebetween.

Abstract: An organic light emitting device and a display apparatus, where the organic light emitting device includes a light-emitting layer, the light-emitting layer includes a host material and a dye, the host material is a triplet-triplet annihilation material, and the dye is the boron-nitrogen material shown in Formula 1. The organic light emitting device has excellent light-emitting efficiency and color purity.

Abstract: An organic electroluminescence device, a preparation method thereof, and a display apparatus, the organic electroluminescence device including 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 a thermally activated delayed fluorescent material. The singlet state energy level of the thermally activated delayed fluorescent material falls between the singlet state energy level of the wide bandgap material and the singlet state energy level of the resonance thermally activated delayed fluorescent material. The triplet state energy level of the thermally activated delayed fluorescent material falls between the triplet state energy level of the wide bandgap material and the triplet state energy level of the resonance thermally activated delayed fluorescent material.

Abstract: An organic electroluminescent device, a preparation method thereof, and a display apparatus. The organic electroluminescent device includes a light emitting layer, the light emitting layer includes a host material and a dye, and the host material is a triplet-triplet annihilation material, the dye includes a thermally activated delayed fluorescence material; a singlet energy level of the triplet-triplet annihilation material is greater than a singlet energy level of the thermally activated delayed fluorescence material; and a triplet energy level of the triplet-triplet annihilation material is smaller than a triplet energy level of the thermally activated delayed fluorescence material. The present application can overcome the defect of short device lifetime caused by high-energy excitons in the device at present.

Abstract: 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.

Abstract: The present disclosure discloses an organic electroluminescent device and a preparation method thereof. The device includes a light-emitting layer, the light-emitting layer includes a host material, an auxiliary host material and a fluorescent dye; the host material is an exciplex prepared by mixing an electron donor material and an electron acceptor material, the auxiliary host material is a thermally activated delayed fluorescence material, a singlet energy level and a triplet energy level of the exciplex are higher than the single energy level and triplet energy level of the auxiliary host material. The above organic electroluminescent device can promote the reverse intersystem crossing of the host material and the auxiliary host material from the triplet excitons to the singlet excitons, enhance the Foster energy transfer, reduce the triplet exciton quenching, therefore the efficiency roll-off of the device is small and the external quantum efficiency is high.

Abstract: The present disclosure relates to display technologies, and particularly discloses an organic electroluminescent device. This organic electroluminescent device includes a light-emitting layer, the light-emitting includes an exciplex composed of a donor molecule and an acceptor molecule, and a wide band gap material for increasing the inter-molecular spacing between the donor molecule and the acceptor molecule. According to the device of the present disclosure, the degree of orbital overlap of HOMO and LUMO of the formed exciplex and the singlet-triplet energy level difference can be reduced, the reverse intersystem crossing rate (KRISC) of the exciplex host can be increased, the Föster energy transferred to the guest molecule can be enhanced, and the efficiency and the lifetime of the device can be improved.

Abstract: The present disclosure relates to the technical field of display, and specifically relates to an organic electroluminescent device, and in particular, to a highly efficient fluorescence device. An organic electroluminescent device includes a hole transport layer, and a light-emitting layer. The hole transport layer and the light-emitting layer has an interface exciplex formed at an interface therebetween.