Consequences of anode interfacial layer deletion. HCl-treated ITO in P3HT:PCBM-based bulk-heterojunction organic photovoltaic devices

Michael D. Irwin, Jun Liu, Benjamin J. Leever, Jonathan D. Servaites, Mark C. Hersam, Michael F. Durstock, Tobin J. Marks

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

In studies to simplify the fabrication of bulk-heterojunction organic photovoltaic (OPV) devices, it was found that when glass/tin-doped indium oxide (ITO) substrates are treated with dilute aqueous HCl solutions, followed by UV ozone (UVO), and then used to fabricate devices of the structure glass/ITO/P3HT:PCBM/LiF/Al, device performance is greatly enhanced. Light-to-power conversion efficiency (Eff) increases from 2.4% for control devices in which the ITO surface is treated only with UVO to 3.8% with the HCl + UVO treatment-effectively matching the performance of an identical device having a PEDOT:PSS anode interfacial layer. The enhancement originates from increases in VOC from 463 to 554 mV and FF from 49% to 66%. The modified-ITO device also exhibits a 4× enhancement in thermal stability versus an identical device containing a PEDOT:PSS anode interfacial layer. To understand the origins of these effects, the ITO surface is analyzed as a function of treatment by ultraviolet photoelectron spectroscopy work function measurements, X-ray photoelectron spectroscopic composition analysis, and atomic force microscopic topography and conductivity imaging. Additionally, a diode-based device model is employed to further understand the effects of ITO surface treatment on device performance.

Original languageEnglish
Pages (from-to)2584-2591
Number of pages8
JournalLangmuir
Volume26
Issue number4
DOIs
Publication statusPublished - Feb 16 2010

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ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

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