Abstract
We synthesized a low band gap alternating copolymer containing electron-rich units (i.e. dithienosiloles and benzodithiophenes) and electron-deficient units (i.e. difluorobenzothiadiazoles) for high performance organic solar cells. The polymer was prepared by the Stille coupling reaction and characterized using 1H NMR, GPC, TGA, UV-visible absorption spectroscopy, and cyclic voltammetry. Solar cells were fabricated in a structure of ITO/PEDOT:PSS/polymer:PC70BM/Al with five different blending ratios of polymer and PC70BM (1:1.5, 1:2, 1:3, 1:3.5 and 1:4 by weight ratio). The best efficiency was achieved from the 1:3 ratio of polymer and PC70BM in the photoactive layer, and TEM revealed that there is an optimal nanoscale phase separation between polymer and PC70BM in the 1:3 ratio blend film.
Original language | English |
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Pages (from-to) | 71-77 |
Number of pages | 7 |
Journal | Polymer (Korea) |
Volume | 39 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2015 Jan 1 |
Keywords
- Alternating copolymer
- Low band gap
- Organic solar cell
- Stille coupling reaction
ASJC Scopus subject areas
- Chemical Engineering(all)
- Polymers and Plastics
- Materials Chemistry