We designed and synthesized three emitters with newly synthesized indole moiety. By photoluminescence measurement, the emitters showed Sky-blue, Green and Yellow emission. Three emitters were tested using the same host material in organic light-emitting device. Because of large difference between singlet energy and triplet energy, blue dopant did not show thermally activated delayed fluorescence (TADF) property. In case of yellow dopant, absolute photoluminescence quantum yield was not enough to show TADF property. Green emitter showed the largest external quantum efficiency, which demonstrated the new indole moiety was suitable for green TADF emitter.