Semiconductor Halogenation in Molecular Highly‐Oriented Layered p–n (n–p) Junctions

Advanced Functional Materials, vol. 32

Abstract

Abstract Organic p–n junctions attract widespread interest in the field of molecular electronics because of their unique optoelectronic singularities. Importantly, the molecular donor/acceptor character is strongly correlated to the degree of substitution, e.g., the introduction of electron‐withdrawing groups. Herein, by gradually increasing the degree of peripheral fluorination on planar, D4h−symmetric iron(II) phthalocyanato (FePc) complexes, the energy level alignment and molecular order is defined in a metal‐supported bilayered Pc‐based junction using photoemission orbital tomography. This non‐destructive method selectively allows identifying molecular levels of the hetero‐architectures. It demonstrates that, while the symmetric fluorination of FePc does not disrupt the long‐range order and degree of metal‐to‐molecule charge transfer in the first molecular layer, it strongly impacts the energy alignment in both the interface and topmost layer in the bilayered structures. The p–n junction formed in the bilayer of perhydrogenated FePc and perfluorinated FeF16Pc may serve as an ideal model for understanding the basic charge‐transport phenomena at the metal‐supported organic–organic interfaces, with possible application in photovoltaic devices.

Authors 8

1. Iulia Cojocariu corresponding

   Forschungszentrum Jülich · Elettra-Sincrotrone Trieste S.C.p.A.

   Affiliation as printed

   Elettra‐Sincrotrone S.C.p.A, S.S 14 – km 163.5 34149 Trieste Italy

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

2. Matteo Jugovac

   Forschungszentrum Jülich · Elettra-Sincrotrone Trieste S.C.p.A.

   Affiliation as printed

   Elettra‐Sincrotrone S.C.p.A, S.S 14 – km 163.5 34149 Trieste Italy

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

3. Sidra Sarwar Aachen Institute of Inorganic Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University 52056 Aachen Germany

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

4. Jeff Rawson Aachen Institute of Inorganic Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University 52056 Aachen Germany

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

5. Sergio Sanz

   Forschungszentrum Jülich

   Affiliation as printed

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

6. Paul Kögerler Aachen Institute of Inorganic Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University 52056 Aachen Germany

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

7. Vitaliy Feyer corresponding

   Forschungszentrum Jülich · University of Duisburg-Essen

   Affiliation as printed

   Fakultät f. Physik and Center for Nanointegration Duisburg‐Essen (CENIDE) Universität Duisburg‐Essen 47048 Duisburg Germany

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

8. Claus Michael Schneider

   Forschungszentrum Jülich · University of Duisburg-Essen · University of California, Davis

   Affiliation as printed

   Dept. of Physics and Astronomy UC Davis Davis CA 95616 USA

   Fakultät f. Physik and Center for Nanointegration Duisburg‐Essen (CENIDE) Universität Duisburg‐Essen 47048 Duisburg Germany

   Peter Grünberg Institute (PGI‐6) Forschungszentrum Jülich GmbH 52428 Jülich Germany

   Dept. of Physics and Astronomy, UC Davis, Davis, CA, 95616 USA