The formation of a well-defined, reproducible ZnO nanorod scaffold for hybrid photovoltaic applications has been investigated. A standard hydrothermal growth method was used and the influence of chemical additions in controlling length, width, density, and orientation was studied. The nanostructures prepared have been characterized by scanning electron microscopy, x-ray diffraction, UV-visible spectroscopy in addition to measurement of the wetting behavior. A standard procedure for the production of vertically orientated nanorods with a narrow size distribution, high areal density, and good wettability in aqueous solutions is presented.
We introduce a novel nanostructuring method for bulk heterojunction solar cells which is aimed at overcoming current
limitations associated with short exciton diffusion lengths and poor charge transport. By employing a nanosphere
templating technique porous interconnected films of copper phthalocyanine (CuPc) have been prepared. Subsequent
infiltration of the CuPc structures with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) results in the formation of
three dimensionally structured nanocomposites, consisting of interpenetrating and interconnected networks. The
lengthscale separation in the composite can be engineered to match exciton diffusion lengths and the interconnectivity is
compatible with good charge transport. We propose this templating strategy as a widely applicable solution to the
continued development of low-cost organic photovoltaics.
We describe a simple technique for the selective area modification of the bandgap in planar 3-D photonic crystals (PhC). The PhCs are grown by controlled drying of monosized polystyrene spheres. Uniaxial pressure of 41 MPa can produce a shift in the bandgap of ~90 nm from 230 nm spheres. An unexpected broadening of the bandgap is attributed to the change in topology associated with large necks formed between spheres at pressures greater than 10 MPa.