HIGHLY EFFICIENT ORGANIC ELECTROLUMINESCENT DEVICE

摘要

The present invention comprises a first electrode, a second electrode, a hole-transport layer, an electron transport layer, and a light emitting layer. In the organic electroluminescent device in which the light emitting layer includes a host and a dopant, the HOMO energy level difference between the host and the hole-transport material of the hole-transport layer is below 0.2eV. The difference in LUMO energy level between the host and the electron transport material of the electron transport layer is below 0.2eV. The difference in LUMO energy level between the host and the hole-transport material of the hole-transport layer is above 0.2eV. The difference in HOMO energy level between the host and the electron transport material of the electron transport layer is above 0.2eV. The organic electroluminescent device is characterized in that the hole-transport material of the hole-transport layer has a triplet energy greater than that of the dopant, and the electron transport material of the electron transport layer has a triplet energy greater than that of the dopant. The highly efficient organic electroluminescent device of the present invention can keep the balance of electric charges similar according to the voltage, acquire the balance of electric charges in the light emitting layer, and bind excitons in the light emitting layer, thereby implementing high efficiency.