Abstract
In this paper, the electronic properties of as-deposited and N${}_{2}$-exposed CuPc/F${}_{16}$CuPc interface, a prototype system for organic photovoltaic applications, are investigated by using ultralow background, high-sensitivity photoemission spectroscopy. It is found that (i) N${}_{2}$ exposure significantly modifies the energy level alignment (ELA) at the interface between CuPc and F${}_{16}$CuPc layer and (ii) the direction of the N${}_{2}$-induced energy level shift of the CuPc depends on the position of the Fermi level (${E}_{F}$) in the CuPc highest occupied molecular orbital-lowest unoccupied molecular orbital gap of the as-deposited film. These observations are related to the changes in the density of gap states (DOGS) produced by structural imperfections in the molecular packing geometry, as introduced by the N${}_{2}$ penetration into the CuPc layer. This result demonstrates the key role of structure-induced DOGS in controlling the ELA at organic/organic interfaces.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.