A Sandwich Mixed (Phthalocyaninato) (Porphyrinato) Europium Triple-Decker: Balanced-Mobility, Ambipolar Organic Thin-Film Transistor

Abstract This study describes the synthesis and characterization of a new triple-decker (phthalocyaninato) (porphyrinato) europium organic thin-film transistor (OTFT) (MPyPP)Eu2[Pc(OPh)8]2 (1) [MPyPP is 5-pyridyl-10,15,20-triphenylporphyrin dianion; Pc(OPh)8 is 2,3,9,10,16,17,23,24-octa(phenoxy)phthalocyanine dianion]. The structure of 1 was confirmed using 1H NMR, MALDI-TOF, UV-Vis, and IR spectroscopy. The redox properties of 1 were investigated using cyclic voltammetry (CV). The designed triple-decker geometry was obtained through the coordination of Eu3+ ion with phthalocyanine N atoms of n-type (Eu[Pc(OPh)8]2) and p-type porphyrin (MPyPP) unit. The obtained complex was soluble in common organic solvents. As seen from CV measurements of 1, triple-decker orientation modifies HOMO and LUMO energies to fit the range acceptable for the organic, ambipolar semiconductors. The thin films of 1 were prepared following quasi–Langmuir–Shafer (QLS) solution-based procedure. UV/Vis, XRD characterized the QLS films and SEM, indicating the ordered, crystalline structure of (MPyPP)Eu2[Pc(OPh)8]2 units. The ambipolar properties of OTFT produced from triple-decker phthalocyanine/porphyrin europium complex via the solution-based QLS method have been revealed for the first time. The fabricated thin films showed well-balanced mobility for holes (0.05 cm2 V–1 s–1) and electrons (0.12 cm2 V–1 s–1).