A light emitting device comprising an anode, an emissive layer, an electron transporting layer and a cathode that are provided as layers in turn, the device emits light by electrical energy and said electron transporting layer comprises {HEAD ~ at least one type} of {TAIL ~ compound} comprising a plurality of 1,7 phenanthroline skeletal structures or a plurality of benzoquinoline skeletal structures, wherein said plurality of 1,7 phenanthroline skeletal structures or a plurality of benzoquinoline skeletal structures are connected by conjugated bonds, an aromatic hydrocarbon, an aromatic heterocycle or combinations thereof 
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A light emitting device comprising an anode , an emissive layer , an electron transporting layer and a cathode that are provided as layers in turn , the device emits light by electrical energy and said electron transporting layer comprises { HEAD ~ at least one type } of { TAIL ~ compound } comprising a plurality of 1,7 phenanthroline skeletal structures or a plurality of benzoquinoline skeletal structures , wherein said plurality of 1,7 phenanthroline skeletal structures or a plurality of benzoquinoline skeletal structures are connected by conjugated bonds , an aromatic hydrocarbon , an aromatic heterocycle or combinations thereof
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