Nanoparticle self-assembly in three dimensions in polymer-based solar cells
When nanoparticles self-assemble to interfaces they are stabilized by entropic and enthalpic forces. These forces are so great that they allow a polymer film to assemble over ca. 100 nm sized objects on an otherwise flat surface thereby making a film that does not dewet the rough substrate. The reason is that disassembling the nanoparticle layer requires more energy than that gained by dewetting from the rough substrate. This phenomenon is being used to generate a bulk heterojunction containing nanoparticles and conducting polymer to increase the interfacial area and thereby aid exciton dissociation making a more efficient solar cell.
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