Hybrid materials from diaminopyriminide-functionalized poly(hexylthiophene) and thymine-capped CdSe nanocrystals: Part II - Hydrogen bond assisted layer-by-layer molecular level processing

The hydrogen bonds directed molecular recognition phenomenon between 1-(6-mercaptohexyl)thymine-capped cadmium selenide nanocrystals and diaminopyrimidine-functionalized poly(alkylthiophene), that is, poly(3-hexylthiophene-co-oxy diaminopyrimidine-hexylthiophene), is exploited in the layer-by-layer assembly of these components to yield a new organic/inorganic electroactive hybrid material. The elaborated molecular processing method allows for the fabrication of composite thin films of precisely controlled thickness and low surface roughness without the necessity of the substrate's surface functionalization before the deposition of the first layer. Complementary scanning electron microscopy and small-angle X-ray scattering investigations of the deposited layers indicate that the polymer and the nanocrystal phases form a quasi-interpenetrating network, which is favorable for their application in photovoltaic devices relying on the bulk heterojunction concept.