Band tail recombination in polymer: Fullerene organic solar cells

Steven A. Hawks, Gang Li, Yang Yang, Robert A. Street

Research output: Journal article publicationJournal articleAcademic researchpeer-review

38 Citations (Scopus)

Abstract

Recombination through band tail localized states is studied analytically and by measurement of the forward-bias dark current as a function of temperature in three different organic bulk-heterojunction solar cells. The Shockley-Read-Hall mechanism is analyzed for the specific case of recombination between mobile carriers and an exponential distribution of localized band tail states. The analysis gives a simple relation between the dark current ideality factor and the band tail slope. Assumptions of the model are verified by numerical drift-diffusion modeling. Diode current-voltage measurements give good agreement with the analytical model, confirming that the band tail recombination mechanism applies to at least some organic solar cells. Deep traps provide a secondary recombination channel in some devices.
Original languageEnglish
Article number074503
JournalJournal of Applied Physics
Volume116
Issue number7
DOIs
Publication statusPublished - 21 Aug 2014
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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