Effects of Nanostructure Geometry on Nanoimprinted Polymer Photovoltaics



We demonstrate the effects of nanostructure geometry on the nanoimprint induced poly(3-hexylthiophene-2,5-diyl) (P3HT) chain alignment and the performance of nanoimprinted photovoltaic devices. Out-of-plane and in-plane grazing incident X-ray diffraction techniques are employed to characterize the nanoimprint induced chain alignment in P3HT nanogratings with different widths, spacings and heights. We observe the dependence of the crystallite orientation on nanostructure geometry such that a larger width of P3HT nanogratings leads to more edge-on chain alignment while the increase in height gives more vertical alignment. Consequently, P3HT/6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) solar cells with the highest density and aspect ratio P3HT nanostructures show the highest power conversion efficiency among others, which is attributed to the efficient charge separation, transport and light absorption.


Walter Hu is also known as Wenchuang Hu,
Includes supplementary material


Poly(3-hexylthiophene-2,5-diyl), Nanogratings, Chains (Chemistry), Nanostructures, Polymers


"This work is supported by NSF (grant no. ECCS-0901759), Welch Foundation Grant AT-1617, and DOE Phase II STTR program on “Tandem Organic Solar Cells” (grant no. DE-SC00003664)."


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