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Understanding the loss mechanisms in high-performance solution-processed small molecule bulk heterojunction solar cells doped with a PFN impurity

Journal Article


Abstract


  • Contamination of the active layer with an impurity could result in significant degradation in the

    performance of bulk heterojunction (BHJ) solar cells as a result of enhancing the loss of the charge carriers

    via a trap-assisted recombination. In this study, PFN as an impurity was intentionally introduced to a BHJ

    solar cell composed of a high-performance solution-processed small molecule (p-DTS(FBTTh2)2 as a donor

    and PC60BM as an acceptor. The power conversion efficiency (PCE) of PFN doped devices degrades owing

    to the reduction of short-circuit current (Jsc) and fill factor (FF). At a low concentration, PFN mostly reduces

    the generation of charge carriers, whereas doubling the PFN concentration conversely affects both

    generation and collection of charge carriers. Charge carrier dynamics of devices has also been probed

    using photovoltage decay, time-resolved charge extraction (TRCE) and photoinduced charge extraction by

    linearly increasing voltage (photo-CELIV) before and after incorporation of PFN. The results reveal that traps

    introduced by PFN reduce the decay of charge carriers via bimolecular recombination, leading to a higher

    charge carrier density and photovoltage at long times under an open-circuit potential (Voc). However,

    under short-circuit (Jsc) conditions, traps considerably impede the collection of charge carriers causing the

    appearance of an S-shaped current density–voltage curve.

Authors


Publication Date


  • 2019

Citation


  • Aghassi, A. & Fay, C. C. (2019). Understanding the loss mechanisms in high-performance solution-processed small molecule bulk heterojunction solar cells doped with a PFN impurity. Physical Chemistry Chemical Physics, 21 (24), 13176-13185.

Scopus Eid


  • 2-s2.0-85068112231

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/3707

Number Of Pages


  • 9

Start Page


  • 13176

End Page


  • 13185

Volume


  • 21

Issue


  • 24

Place Of Publication


  • United Kingdom

Abstract


  • Contamination of the active layer with an impurity could result in significant degradation in the

    performance of bulk heterojunction (BHJ) solar cells as a result of enhancing the loss of the charge carriers

    via a trap-assisted recombination. In this study, PFN as an impurity was intentionally introduced to a BHJ

    solar cell composed of a high-performance solution-processed small molecule (p-DTS(FBTTh2)2 as a donor

    and PC60BM as an acceptor. The power conversion efficiency (PCE) of PFN doped devices degrades owing

    to the reduction of short-circuit current (Jsc) and fill factor (FF). At a low concentration, PFN mostly reduces

    the generation of charge carriers, whereas doubling the PFN concentration conversely affects both

    generation and collection of charge carriers. Charge carrier dynamics of devices has also been probed

    using photovoltage decay, time-resolved charge extraction (TRCE) and photoinduced charge extraction by

    linearly increasing voltage (photo-CELIV) before and after incorporation of PFN. The results reveal that traps

    introduced by PFN reduce the decay of charge carriers via bimolecular recombination, leading to a higher

    charge carrier density and photovoltage at long times under an open-circuit potential (Voc). However,

    under short-circuit (Jsc) conditions, traps considerably impede the collection of charge carriers causing the

    appearance of an S-shaped current density–voltage curve.

Authors


Publication Date


  • 2019

Citation


  • Aghassi, A. & Fay, C. C. (2019). Understanding the loss mechanisms in high-performance solution-processed small molecule bulk heterojunction solar cells doped with a PFN impurity. Physical Chemistry Chemical Physics, 21 (24), 13176-13185.

Scopus Eid


  • 2-s2.0-85068112231

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/3707

Number Of Pages


  • 9

Start Page


  • 13176

End Page


  • 13185

Volume


  • 21

Issue


  • 24

Place Of Publication


  • United Kingdom