The Importance of Morphology Control

Since the photoactive layer is deposited from solution, the morphology determining features are of thermodynamic and kinetic nature, the latter mainly playing a role during the film formation process. Thermodynamic aspects are reflected in the chemical structure of the donor and acceptor compounds determining to a large extent their solubility in different solvents and the interaction (miscibility) 

Moiectiler arctmectM j (nialch d barxl properties /— Y tideeer 0 A) 

Malenal properties (etacIronAiole mobilities, amorphous or crystaleie) 

The Classic Blend MDMO-PPV/PCBM as a Model for an Amorphous Donor System 

However, it has been shown that the dynamics of reorganization of a thin film upon thermal treatment not only is determined by the composition and organization of the film itself, but also depends on its local environment. Numerous experiments indicate that the mobility of polymer molecules in the vicinity of a surface or an interface is perturbed [16-18], and the extent to which they affect the mobility of polymer chains depends on the strength of their interactions with the surface/interface. 

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X. Yang, J. Loos, Towards high-performance polymer solar cells the importance of morphology control. Macromolecules, 40, 1353-1362 (2007). 

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