An electroluminescent device is disclosed comprising in sequence, an anode, an organic hole injecting and transporting zone, an organic electron injecting and transporting zone, and a cathode. The organic hole injecting and transporting zone is comprised of a layer in contact with the anode containing...http://www.google.com/patents/US4720432?utm_source=gb-gplus-sharePatent US4720432 - Electroluminescent device with organic luminescent medium
