title: Long-Term Stable Recombination Layer for Tandem Polymer Solar Cells Using Self-Doped Conducting Polymers.
abstract: Recently, the most efficient tandem polymer solar cells (PSCs) have used poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (
  PSS) as a p-type component of recombination layer (RL). However, its undesirable acidic nature, originating from insulating PSS, of
  PSS drastically reduces the lifetime of PSCs. Here, we demonstrate the efficient and stable tandem PSCs by introducing acid-free self-doped conducting polymer (SCP), combined with zinc oxide nanoparticles (ZnO NPs), as RL for
  PSS-free tandem PSCs. Moreover, we introduce an innovative and versatile nanocomposite system containing photoactive and p-type conjugated polyelectrolyte (p-CPE) into the tandem fabrication of an ideal self-organized recombination layer. In our new RL, highly conductive SCP facilitates charge transport and recombination process, and p-CPE helps to achieve nearly loss-free charge collection by increasing effective work function of indium tin oxide (ITO) and SCP. Because of the synergistic effect of extremely low electrical resistance, ohmic contact, and pH neutrality, tandem devices with our novel RL performed well, exhibiting a high power conversion efficiency of 10.2% and a prolonged lifetime. These findings provide a new insight for strategic design of RLs using SCPs to achieve efficient and stable tandem PSCs and enable us to review and extend the usefulness of SCPs in various electronics research fields.
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Jinho
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Hongkyu
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Seyoung
authors.initials: S
authors.lastname: Kee
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Seoung Ho
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Song Yi
authors.initials: SY
authors.lastname: Jeong
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Geunjin
authors.initials: G
authors.lastname: Kim
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Junghwan
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Soonil
authors.initials: S
authors.lastname: Hong
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Hyungcheol
authors.initials: H
authors.lastname: Back
authors.affiliation: Department of Nanobio Materials and Electronics (DNE), School of Materials Science and Engineering (SMSE) and ‡Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST) , Gwangju 500-712, Korea.
authors.forename: Kwanghee
authors.initials: K
authors.lastname: Lee
keywords: conjugated polyelectrolyte; lifetime; recombination layer; self-doped; tandem polymer solar cell