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In situ space-resolved X-ray diffraction and time-resolved EDXD on efficient polymer-based photovoltaic devices: Microstructural properties and aging effects

Published online by Cambridge University Press:  24 January 2017

Francesco Silvestri ,
Amanda Generosi ,
Marco Guaragno ,
Valerio Rossi Albertini ,
Claudio Ferrero ,
Gianpaolo Susanna ,
Francesca Brunetti ,
Ivan Davoli  and
Barbara Paci
Francesco Silvestri
Affiliation:
Dipartimento di Fisica, Università di Roma “Tor Vergata” Via della Ricerca Scientifica 1, Italy
Amanda Generosi
Affiliation:
Istituto di Struttura della Materia ISM-CNR, Via del Fosso del Cavaliere 100, Roma 00133, Italy
Marco Guaragno
Affiliation:
Istituto di Struttura della Materia ISM-CNR, Via del Fosso del Cavaliere 100, Roma 00133, Italy
Valerio Rossi Albertini
Affiliation:
Istituto di Struttura della Materia ISM-CNR, Via del Fosso del Cavaliere 100, Roma 00133, Italy
Claudio Ferrero
Affiliation:
ESRF—The European Synchrotron 71, av. des Martyrs, Grenoble Cedex 38043, France
Gianpaolo Susanna
Affiliation:
CHOSE-Center for Hybrid and Organic Solar Energy, Department of Electronics Engineering, Università di Roma, Tor Vergata, Via del Politecnico 1, Roma 00133, Italy
Francesca Brunetti
Affiliation:
CHOSE-Center for Hybrid and Organic Solar Energy, Department of Electronics Engineering, Università di Roma, Tor Vergata, Via del Politecnico 1, Roma 00133, Italy
Ivan Davoli
Affiliation:
Dipartimento di Fisica, Università di Roma “Tor Vergata” Via della Ricerca Scientifica 1, Italy
Barbara Paci*
Affiliation:
Istituto di Struttura della Materia ISM-CNR, Via del Fosso del Cavaliere 100, Roma 00133, Italy
*
a) Address all correspondence to this author. e-mail: Barbara.paci@ism.cnr.it
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Abstract

Microstructural and morphological features of the layers forming integrated PTB7/PC71BM organic solar cells with Ca/Al cathode are studied. The effects of vacuum treatment on properties and durability were addressed using complementary approaches: time-resolved experiments revealing the structural evolution of the active layers under illumination were conducted combining the in situ energy dispersive X-ray diffraction (EDXD) technique with atomic force microscopy (AFM); space-resolved characterization of the integrated devices was possible via high resolution X-ray diffraction, using a nano-focused synchrotron radiation X-ray beam to discriminate the device components. Active layers surface morphology is stable under illumination and PC71BM structural properties remain unaltered. PTB7 undergoes crystallinity depletion, mainly at the active layer/cathode interface. This effect is actually inhibited in the device submitted to vacuum treatment, proving that this procedure induces stabilization at the cathode’s buried interface, as verified by fourier transform infrared (FTIR) spectroscopy. Importantly, the protective role of the vacuum treatment results in a significant photovoltaic durability enhancement.

Keywords

organic photovoltaic devicesstructural and morphological propertiesefficiency enhancementstability enhancementspatially resolved in situ X-ray characterization
Type
Article
Information
Journal of Materials Research , Volume 32 , Issue 10: Focus Issue: Microstructural Characterization for Emerging Photovoltaic Materials , 26 May 2017 , pp. 1969 - 1981
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Copyright
Copyright © Materials Research Society 2017 

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Footnotes

Contributing Editor: Moritz Riede

References

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