Post-assembly atomic layer deposition of ultrathin metal-oxide coatings enhances the performance of an organic dye-sensitized solar cell by suppressing dye aggregation

Ho Jin Son, Chul Hoon Kim, Dong Wook Kim, Nak Cheon Jeong, Chaiya Prasittichai, Langli Luo, Jinsong Wu, Omar K. Farha, Michael R. Wasielewski, Joseph T. Hupp

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29 Citations (Scopus)


Dye aggregation and concomitant reduction of dye excited-state lifetimes and electron-injection yields constitute a significant mechanism for diminution of light-to-electrical energy conversion efficiencies in many dye-sensitized solar cells (DSCs). For TiO2-based DSCs prepared with an archetypal donor-acceptor organic dye, (E)-2-cyano-3-(5′-(5′′-(p-(diphenylamino)phenyl)-thiophen-2′′-yl)thiophen-2′-yl)acrylic acid (OrgD), we find, in part via ultrafast spectroscopy measurements, that postdye-adsorption atomic layer deposition (ALD) of ultrathin layers of either TiO2 or Al2O3 effectively reverses residual aggregation. Notably, the ALD treatment is significantly more effective than the widely used aggregation-inhibiting coadsorbent, chenodeoxycholic acid. Primarily because of reversal of OrgD aggregation, and resulting improved injection yields, ALD post-treatment engenders a 30+% increase in overall energy conversion efficiency. A secondary contributor to increased currents and efficiencies is an ALD-induced attenuation of the rate of interception of injected electrons, resulting in slightly more efficient charge collection.

Original languageEnglish
Pages (from-to)5150-5159
Number of pages10
JournalACS Applied Materials and Interfaces
Issue number9
Publication statusPublished - Mar 11 2015



  • atomic layer deposition (ALD)
  • dye aggregation
  • dye-sensitized solar cells (DSCs)
  • interfacial electron injection
  • post-treatment

ASJC Scopus subject areas

  • Materials Science(all)

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