Impact of Fullerene Molecular Weight on P3HT:PCBM Microstructure Studied Using Organic Thin-Film Transistors
✍ Scribed by John G. Labram; James Kirkpatrick; Donal D. C. Bradley; Thomas D. Anthopoulos
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 828 KB
- Volume
- 1
- Category
- Article
- ISSN
- 1614-6832
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✦ Synopsis
Abstract
The clustering and diffusion of C~71~‐butyric acid methyl ester (PC~71~BM) in poly(3‐hexylthiophene) (P3HT) has been studied using single layer blend and bilayer organic field‐effect transistors (OFETs) and by atomic force microscopy (AFM). P3HT:PC~71~BM blend based OFETs were found to undergo phase‐segregation upon annealing, which was detectable as a fall in electron mobility with increasing annealing temperature. By employing carefully designed bilayer P3HT:PC~71~BM OFETs, the diffusion‐properties of PC~71~BM in P3HT could additionally be inferred from electron mobility measurements. It was found that the prerequisite annealing temperatures for detectable PC~71~BM clustering and diffusion in P3HT was approximately 20 °C higher than for PC~61~BM. The diffusion coefficient of PC~61~BM in P3HT was found to be several times higher that that of PC~71~BM. The present work provides unique insights into the diffusion process of fullerenes in conjugated polymers and could prove highly valuable for future materials development and device optimization.