Layer-by-layer graphene/TCNQ stacked films as conducting anodes for organic solar cells

ACS Nano. 2012 Jun 26;6(6):5031-9. doi: 10.1021/nn301721q. Epub 2012 Jun 1.

Abstract

Large-area graphene grown by chemical vapor deposition (CVD) is a promising candidate for transparent conducting electrode applications in flexible optoelectronic devices such as light-emitting diodes or organic solar cells. However, the power conversion efficiency (PCE) of the polymer photovoltaic devices using a pristine CVD graphene anode is still not appealing due to its much lower conductivity than that of conventional indium tin oxide. We report a layer-by-layer molecular doping process on graphene for forming sandwiched graphene/tetracyanoquinodimethane (TCNQ)/graphene stacked films for polymer solar cell anodes, where the TCNQ molecules (as p-dopants) were securely embedded between two graphene layers. Poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester (P3HT/PCBM) bulk heterojunction polymer solar cells based on these multilayered graphene/TCNQ anodes are fabricated and characterized. The P3HT/PCBM device with an anode structure composed of two TCNQ layers sandwiched by three CVD graphene layers shows optimum PCE (∼2.58%), which makes the proposed anode film quite attractive for next-generation flexible devices demanding high conductivity and transparency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electric Conductivity
  • Electric Power Supplies*
  • Electrodes*
  • Equipment Design
  • Equipment Failure Analysis
  • Graphite / chemistry*
  • Membranes, Artificial*
  • Nitriles / chemistry*
  • Solar Energy*

Substances

  • Membranes, Artificial
  • Nitriles
  • tetracyanoquinodimethane
  • Graphite