Abstract
We show how the work function of transparent conductive oxide surfaces can be increased by more than 1 eV by solution-depositing strong electron acceptor monolayers comprising tetrafluoro-tetracyanoquinodimethane (F4TCNQ) or hexaazatriphenylene-hexacarbonitrile (HATCN). The effects of ambient atmosphere on the work function are investigated by comparing Kelvin probe measurements in air and ultraviolet photoelectron spectroscopy in ultrahigh vacuum. In this way, important technological issues related to the influence of ambient moisture on electrode properties are elucidated.
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Acknowledgments
The authors thank S. Janietz and B. Gruber for granting access to PYS at the Fraunhofer-IAP (Potsdam-Golm/ Germany), and to J. P. Rabe for granting access to the UPS/XPS setup. This work was supported by the DFG (SPP1355 and SFB951), and the Helmholtz-Energie-Allianz “Hybrid-Photovoltaik”.
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Castellani, M., Winkler, S., Bröker, B. et al. Work function increase of transparent conductive electrodes by solution processed electron acceptor molecular monolayers. Appl. Phys. A 114, 291–295 (2014). https://doi.org/10.1007/s00339-013-8048-x
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DOI: https://doi.org/10.1007/s00339-013-8048-x