The initial OLEDs used {HEAD ~ emissive molecules} that emitted {TAIL ~ light} from their singlet states as disclosed, for example, in U.S. Pat 
emitted
The initial OLEDs used { HEAD ~ emissive molecules } that emitted { TAIL ~ light } from their singlet states as disclosed , for example , in U.S. Pat
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH