Manipulating interfaces in a hybrid solar cell by in situ photosensitizer polymerization and sequential hydrophilicity/hydrophobicity control for enhanced conversion efficiency

The polyacetylene photosensitizer with quaternary pyridinium salts was layered on CdS nanoparticles films by in situ polymerization of 2-ethynylpyridine and 4-bromobutyric acid. The hydrophilic nature of the polyacetylene is shown to enhance the interfacial contact and electrical coupling between hydrophilic CdS and the polymer. The hydrophilicity of the polymer was modified toward hydrophobicity by anion exchange in order to adequately layer the hydrophobic poly (3-hexylthiophene) by spin coating, power-conversion efficiency 1.18% (AM1.5, I=100 mW/cm(2)). (C) 2008 American Institute of Physics.