Abstract
A comparison of grazing incidence wide-angle X-ray scattering (GiWAXS) and differential scanning calorimetric measurements (DSC) was used to identify the influence of a dominantly amorphous small band gap polymer material poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene) -alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) on the crystallinity of a semi-crystalline polymer/fullerene composite. In binary blends the low band gap polymer does not influence the crystalline part of P3HT, but does influence the crystallinity of the fullerene. In ternary blends, a significant drop of the PCBM crystallinity is observed with increasing PCPDTBT content. Adding more than 20 wt% PCPDTBT to a P3HT:PCBM blend leads to a dramatic reduction of device efficiency, mainly due to short circuit current density and fill factor losses. This deterioration is attributed to the fact that addition of more than 20 wt% PCPDTBT to the host system strongly reduces crystallinity of the fullerene phase and electron transport in the ternary system. © 2012 The Royal Society of Chemistry.
Original language | English |
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Pages (from-to) | 15570-15577 |
Number of pages | 8 |
Journal | Journal of Materials Chemistry |
Volume | 22 |
Issue number | 31 |
DOIs | |
Publication status | Published - 2012 |
Keywords
- 2
- 1
- 3-Benzothiadiazole
- Binary blends
- Crystallinities
- Device efficiency
- Differential scanning calorimetric measurements
- Electron transport
- Fill factor
- Grazing incidence
- Low bandgap polymers
- Organic photovoltaic devices
- Semi-crystalline polymer
- Small band gap polymer
- Ternary blends
- Wide angle X-ray scattering
- Crystalline materials
- Energy gap
- Fullerenes
- Polymer blends
- Polymers