It will be appreciated that although for convenience {HEAD ~ the OLEDs} in {TAIL ~ accordance} with the invention are described as having top and bottom multilayer stacks, they can be oriented in any manner 
in
It will be appreciated that although for convenience { HEAD ~ the OLEDs } in { TAIL ~ accordance } with the invention are described as having top and bottom multilayer stacks , they can be oriented in any manner
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL 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