Surface modification of SnO2 photoelectrodes in dye-sensitized solar cells: Significant improvements in photovoltage via Al2O 3 atomic layer deposition

Chaiya Prasittichai, Joseph T. Hupp

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Abstract

We report here the exploitation of ultrathin layers of Al2O 3 deposited via atomic layer deposition (ALD) on SnO2 photoanodes used in dye-sensitized solar cells featuring the I3 -/I- couple as the redox electrolyte. We find that a single ALD cycle of Al2O3 increases the lifetimes of injected electrons by more than 2 orders of magnitude. The modified SnO 2 photoanode yields nearly a 2-fold improvement fill factor and a greater than 2-fold increase in open-circuit photovoltage, with a slight increase in short-circuit photocurrent. The overall energy conversion efficiency increases by roughly 5-fold. The effects appear to arise primarily from passivation of reactive, low-energy tin-oxide surface states, with band-edge shifts and tunneling based blocking behavior playing only secondary roles.

Original languageEnglish
Pages (from-to)1611-1615
Number of pages5
JournalJournal of Physical Chemistry Letters
Volume1
Issue number10
DOIs
Publication statusPublished - May 20 2010

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ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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