[18p-P11-1~13] 12.2 Characterization and Materials Physics

▲ [18p-P11-4] Influence of the Work Function of the Substrate in the Energy-Level Alignment at Organic-Organic Heterojunction Interface

〇(D)Alexandre Foggiatto¹, Takahiro Ueba², Satoshi Kera^2,3, Takeaki Sakurai¹ (1.Univ. of Tsukuba, 2.IMS, 3.Chiba Univ.)

Keywords:organic semiconductor, energy-level alignment

In the past years, many works have been dedicated to understand the origin of the band bending in organic thin films and the energy-level alignment (ELA) at organic-inorganic and organic-organic heterojunction (OOH) interfaces. In this work, we are interested in understanding the influence of the substrate work function (WF) at donor/acceptor interface and the role of the tail states in the ELA. To do so, we used X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS) to study the ELA of boron subphthalocyanine chloride (SubPc)/ α-sexithiophene (6T) deposited on MoO₃ and Cs₂CO₃. Their work function values are 5.9, 4.0, 3.0 eV, respectively. The ionization potential (IP) of SubPc and 6T were measured as 5.7 and 4.7 eV, respectively.