Exciton dynamics and device performance in polythiophene heterojunctions for photovoltaics

Stephanie V. Chasteen, Sue A. Carter, Gary Rumbles

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

We present time-resolved photo luminescence studies in conjunction with device characterization of a variety of heterojunctions with poly-(3-hexylthiophene), or P3HT, as a means to understand how exciton dynamics affect device performance. We find that blends of P3HT with the electron-transporting polymer CN-ether-PPV and with the fullerene derivative PCBM result in ∼4-fold and ∼15-fold improvements in short-circuit currents, respectively, over neat-film P3HT on TiO 2 solgel. Despite efficient charge-transfer in P3HT:PCBM films, as evidenced by enhanced device performance and quenched steady-state luminescence, we observe only moderate reduction of the excited state lifetime, due to the already efficient non-radiative pathways in P3HT. We observe evidence for a new state that we assign to an exciplex in blends of P3HT with the electron-transporting polymer CN-ether-PPV. The exciplex state, which confirms the existence of charge-transfer between the two polymers, may account for the enhanced device performance of these blends by acting as a scavenger for excitons that would otherwise decay rapidly via non-radiative pathways. The long-range order of P3HT is disrupted when spin-cast on rough TiO 2 nanoparticles, and this results in a blueshift of the PL spectrum and a new long-lived decay component that we attribute to long-lived intrachain polarons. P3HT on smooth TiO 2 solgel films shows little or no quenching of the excited state, despite known charge transfer from P3HT to TiO 2.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsZ.H Kafafi, P.A. Lane
Pages1-11
Number of pages11
Volume5938
DOIs
Publication statusPublished - 2005
EventOrganic Photovoltaics VI - San Diego, CA, United States
Duration: Aug 2 2005Aug 4 2005

Other

OtherOrganic Photovoltaics VI
CountryUnited States
CitySan Diego, CA
Period8/2/058/4/05

Fingerprint

Excitons
Heterojunctions
Charge transfer
heterojunctions
excitons
Excited states
Ethers
charge transfer
Polymers
ethers
Polarons
polymers
Electrons
Fullerenes
Short circuit currents
Luminescence
Quenching
Photoluminescence
polarons
decay

Keywords

  • CN-ether-PPV
  • Conjugated polymers
  • Fullerene
  • P3HT
  • PCBM
  • Photovoltaic effect
  • Plastic electronics
  • Polymer solar cell
  • Time-resolved photoluminescence
  • Titanium dioxide

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Chasteen, S. V., Carter, S. A., & Rumbles, G. (2005). Exciton dynamics and device performance in polythiophene heterojunctions for photovoltaics. In Z. H. Kafafi, & P. A. Lane (Eds.), Proceedings of SPIE - The International Society for Optical Engineering (Vol. 5938, pp. 1-11). [59380J] https://doi.org/10.1117/12.614243

Exciton dynamics and device performance in polythiophene heterojunctions for photovoltaics. / Chasteen, Stephanie V.; Carter, Sue A.; Rumbles, Gary.

Proceedings of SPIE - The International Society for Optical Engineering. ed. / Z.H Kafafi; P.A. Lane. Vol. 5938 2005. p. 1-11 59380J.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Chasteen, SV, Carter, SA & Rumbles, G 2005, Exciton dynamics and device performance in polythiophene heterojunctions for photovoltaics. in ZH Kafafi & PA Lane (eds), Proceedings of SPIE - The International Society for Optical Engineering. vol. 5938, 59380J, pp. 1-11, Organic Photovoltaics VI, San Diego, CA, United States, 8/2/05. https://doi.org/10.1117/12.614243
Chasteen SV, Carter SA, Rumbles G. Exciton dynamics and device performance in polythiophene heterojunctions for photovoltaics. In Kafafi ZH, Lane PA, editors, Proceedings of SPIE - The International Society for Optical Engineering. Vol. 5938. 2005. p. 1-11. 59380J https://doi.org/10.1117/12.614243
Chasteen, Stephanie V. ; Carter, Sue A. ; Rumbles, Gary. / Exciton dynamics and device performance in polythiophene heterojunctions for photovoltaics. Proceedings of SPIE - The International Society for Optical Engineering. editor / Z.H Kafafi ; P.A. Lane. Vol. 5938 2005. pp. 1-11
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