An OLED device was produced in the same manner as in Example 1, except for using compound H-2 as a host and compound D-73 as a dopant of the luminescent material. As a result, an efficiency of 25.0 cd/A at 1000 nit was shown, and the CIE color coordinate was 0.332, 0.561. It is verified that the device using the organic electroluminescent compound of the present invention as a TADF dopant material has excellent current and luminous efficiencies. The photoluminescence spectrum of compound D-73 was measured in the same manner as in Example 1 and illustrated in FIG. 3. From FIG. 3, it was determined that the ΔE_ST of compound D-73 is 0.03 eV, and thus compound D-73 emits light by delayed fluorescence.

An OLED device was produced in the same manner as in Example 1, except for using compound H-2 as a host and compound D-41 as a dopant of the luminescent material. As a result, an efficiency of 24.4 cd/A at 1000 nit was shown, and the CIE color coordinate was 0.336, 0.557. It is verified that the device using the organic electroluminescent compound of the present invention as a TADF dopant material has excellent current and luminous efficiencies. The photoluminescence spectrum of compound D-41 was measured in the same manner as in Example 1 and illustrated in FIG. 4. From FIG. 4, it was determined that the ΔE_ST of compound D-41 is 0.07 eV, and thus compound D-41 emits light by delayed fluorescence.