A versatile fluoro-containing low-bandgap polymer for efficient semitransparent and tandem polymer solar cells

Chih Yu Chang, Lijian Zuo, Hin Lap Yip, Yongxi Li, Chang Zhi Li, Chain Shu Hsu, Yen Ju Cheng, Hongzheng Chen, Alex K.Y. Jen

Research output: Contribution to journalArticle

87 Citations (Scopus)


The versatility of a fluoro-containing low band-gap polymer, poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4, 7-(5-fluoro-2,1,3-benzothia-diazole)] (PCPDTFBT) in organic photovoltaics (OPVs) applications is demonstrated. High boiling point 1,3,5-trichlorobenzene (TCB) is used as a solvent to manipulate PCPDTFBT:[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) active layer morphology to obtain high-performance single-junction devices. It promotes the crystallization of PCPDTFBT polymer, thus improving the charge-transport properties of the active layer. By combining the morphological manipulation with interfacial optimization and device engineering, the single-junction device exhibits both good air stability and high power-conversion efficiency (PCE, of 6.6%). This represents one of the highest PCE values for cyclopenta[2,1-b;3,4-b']dithiophene (CPDT)-based OPVs. This polymer is also utilized for constructing semitransparent solar cells and double-junction tandem solar cells to demonstrate high PCEs of 5.0% and 8.2%, respectively. The versatility of a fluoro-containing polymer, PCPDTFBT, in diverse organic photovoltaic applications is demonstrated. By combining morphological, interface, and device engineering, the single-junction cell shows both a high power conversion efficiency (PCE) of 6.6% and good air stability. In addition, the applications of PCPDTFBT in highly efficient semitransparent cells (PCE = 5.0%, average visible transmittance (AVT) = 47.3%) and double-junction tandem cells (PCE = 8.2%) are also demonstrated.

Original languageEnglish
Pages (from-to)5084-5090
Number of pages7
JournalAdvanced Functional Materials
Issue number40
Publication statusPublished - Jul 17 2013
Externally publishedYes



  • low bandgap polymers
  • organic electronics
  • polymer solar cells
  • semitransparent solar cells
  • tandem solar cells

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Condensed Matter Physics
  • Electrochemistry

Cite this

Chang, C. Y., Zuo, L., Yip, H. L., Li, Y., Li, C. Z., Hsu, C. S., Cheng, Y. J., Chen, H., & Jen, A. K. Y. (2013). A versatile fluoro-containing low-bandgap polymer for efficient semitransparent and tandem polymer solar cells. Advanced Functional Materials, 23(40), 5084-5090. https://doi.org/10.1002/adfm201301557