Next Step: Although the cells' electron transport was better, their overall light conversion efficiency was low compared to that of some nanoparticle-based solar cells (which have achieved efficiencies of up to 10 percent). Zinc oxide harvests electrons from the dye less efficiently than does titanium dioxide -- a material more commonly used in nano solar cells. The researchers are now making their nanowires out of titanium dioxide, a more challenging manufacturing process. The nanowires also have a smaller surface area than a network of nanoparticles, so they carry less light-absorbing dye. The researchers are consequently shrinking their nanowires to 10 nanometers in diameter so that they can fit more nanowires onto their arrays and increase the total surface area. Yang predicts that with thinner and more numerous titanium wires, his team will be able to achieve a conversion efficiency of 10 percent or more, which could make these nano solar cells a viable source of energy.
Photovoltaics are quite different from thermoelectric. However, given the recent finds from the cloaking piece, the field of photovoltaics is poised to really take off.
The key here is that we are finding new uses for old materials. We have discovered that there are REAL reasons behind the properties of materials. For example, why gold looks the way it does. Why it is the color it is, how brilliant it is. There is something to say about how it is polished, how it is formed. This is all done on a macro scale. Perhaps, with polishing, you can change it on a microscale. however, take it down another step or two, get down to the nanoscale, and if you can make changes to the material you can further change other properties it exhibits.
In the same way a large lump of gold has the property that it exerts greater force (due to the force=mass*acceleration concept) when dropped on your foot. On the nanoscale such changes in size, shape, contour...they all have further affects on the overall material. This is how you turn paper into a superconductor. Or how you make silicone have thermoelectric properties.
I am willing to bet that if we controlled design on even smaller scales, we could further create unkown, fantastic properties within the same old materials that litter the universe.