An OLED device was produced using the luminescent material of the present invention. A transparent electrode indium tin oxide (ITO) thin film (15 Ω/sq) on a glass substrate for an organic light-emitting diode (OLED) device was subjected to an ultrasonic washing with trichloroethylene, acetone, ethanol, and distilled water, sequentially, and then was stored in isopropanol. The ITO substrate was then mounted on a substrate holder of a vacuum vapor depositing apparatus. HIL-1 was introduced into a cell of said vacuum vapor depositing apparatus, and then the pressure in the chamber of said apparatus was controlled to 10^?6 torr. Thereafter, an electric current was applied to the cell to evaporate the above introduced material, thereby evaporating HIL-1 of 60 nm thickness on the ITO substrate. Next, HIL-2 was introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated to have a thickness of 5 nm by applying an electric current to the cell. HTL-1 was deposited to have a thickness of 15 nm, HTL-2 was deposited to have a thickness of 5 nm on HTL-1, and H-11 was further deposited to have a thickness of 5 nm as an electron blocking layer. A light-emitting layer was deposited as follows. H-2 was introduced into one cell of said vacuum vapor depositing apparatus as a host, and compound D-2 was introduced into another cell as a thermally activated delayed fluorescence (TADF) dopant of the present invention. The two materials were evaporated at different rates, so that the dopant was deposited in a doping amount of 15 wt % based on the total amount of the host and dopant to deposit a light-emitting layer having a thickness of 400 nm. ETL-1 was evaporated at another vacuum vapor depositing apparatus to have a thickness of 5 nm on the light-emitting layer, and ETL-2 and lithium quinolate were then introduced into another two cells, evaporated at the doping rate of 30 to 70 wt %, and deposited to have a thickness of 30 nm. Next, after depositing lithium quinolate as an electron injection layer having a thickness of 2 nm, an Al cathode having a thickness of 150 nm was deposited by another vacuum vapor deposition apparatus. Thus, an OLED device was produced. All the materials were those purified by vacuum sublimation at 10^?6 torr. As a result, an efficiency of 38.8 cd/A at 1000 nit was shown, and the CIE color coordinate was 0.345, 0.581.