Thermal stability of poly[2-methoxy-5-(2’-phenylethoxy)-1,4-phenylene vinylene] (MPEPPV):fullerene bulk heterojunction solar cells

J. Vandenbergh, B.S.T. Conings, S. Bertho, J. Kesters, D. Spoltore, S. Esiner, J. Zhao, G. Assche, van, M.M. Wienk, W. Maes, L. Lutsen, B. Van Mele, R.A.J. Janssen, J.V. Manca, D.J.M. Vanderzande

Research output: Contribution to journalArticleAcademicpeer-review

56 Citations (Scopus)
6 Downloads (Pure)

Abstract

To improve the thermal stability of polymer:fullerene bulk heterojunction solar cells, a new polymer, poly[2-methoxy-5-(2'-phenylethoxy)-1,4-phenylenevinylene] (MPE-PPV), has been designed and synthesized, which showed an increased glass transition temperature (Tg) of 111 °C. The thermal characteristics and phase behavior of MPE-PPV:[6,6]-phenyl C61-butyric acid methyl ester ([60]PCBM) blends were investigated by means of modulated temperature differential scanning calorimetry and rapid heating–cooling calorimetry. The thermal stability of MPE-PPV:[60]PCBM solar cells was compared with devices based on the reference MDMO-PPV material with a Tg of 45 °C. Monitoring of the photocurrent–voltage characteristics at elevated temperatures revealed that the use of high-Tg MPE-PPV resulted in a substantial improvement of the thermal stability of the solar cells. Furthermore, a systematic transmission electron microscope study of the active polymer:fullerene layer at elevated temperatures likewise demonstrated a more stable morphology for the MPE-PPV:[60]PCBM blend. Both observations indicate that the use of high-Tg MPE-PPV as donor material leads to a reduced free movement of the fullerene molecules within the active layer of the photovoltaic device. Finally, optimization of the PPV:fullerene solar cells revealed that for both types of devices the use of [6,6]-phenyl C71-butyric acid methyl ester ([70]PCBM) resulted in a substantial increase of current density and power conversion efficiency, up to 3.0% for MDMO-PPV:[70]PCBM and 2.3% for MPE-PPV:[70]PCBM.
Original languageEnglish
Pages (from-to)8470-8478
Number of pages8
JournalMacromolecules
Volume44
Issue number21
DOIs
Publication statusPublished - 2011

Fingerprint Dive into the research topics of 'Thermal stability of poly[2-methoxy-5-(2’-phenylethoxy)-1,4-phenylene vinylene] (MPEPPV):fullerene bulk heterojunction solar cells'. Together they form a unique fingerprint.

Cite this