Functionalized Zinc Porphyrins with Various Peripheral Groups for Interfacial Electron Injection Barrier Control in Organic Light Emitting Diodes oleh Apostolis Verykios, Michael Papadakis, Anastasia Soultati, Maria-Christina Skoulikidou, George Papaioannou, Spyros Gardelis, Ioannis D. Petsalakis, Giannoula Theodorakopoulos, Vasilis Petropoulos, Leonidas C. Palilis, Mihalis Fakis, Nikolaos A. Vainos, Dimitris Alexandropoulos, Dimitris Davazoglou, George Pistolis, Panagiotis Argitis, Athanassios G. Coutsolelos, Maria Vasilopoulou