The emissive substance included in the device is at least one of the following types of {HEAD ~ compounds}: {TAIL ~ a compound} having a plurality of 1,7 phenanthroline skeletal structures; a benzoquinoline derivative; a spiro compound; and a tetraphenylmethane derivative 
The emissive substance included in the device is at least one of the following types of { HEAD ~ compounds } : { TAIL ~ a compound } having a plurality of 1,7 phenanthroline skeletal structures ; a benzoquinoline derivative ; a spiro compound ; and a tetraphenylmethane derivative
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH