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Impact of Fullerene Molecular Weight on P3HT:PCBM Microstructure Studied Using Organic Thin‐Film Transistors
Author(s) -
Labram John G.,
Kirkpatrick James,
Bradley Donal D. C.,
Anthopoulos Thomas D.
Publication year - 2011
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201100413
Subject(s) - materials science , annealing (glass) , bilayer , fullerene , electron mobility , organic field effect transistor , chemical engineering , transistor , nanotechnology , field effect transistor , optoelectronics , membrane , organic chemistry , composite material , chemistry , biochemistry , engineering , physics , quantum mechanics , voltage
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.