Re:A different problem with photovoltaics (Score 2, Interesting)

True, traditional photovoltaics get the same energy out of every color photon as long as it has enough energy to clear the bandgap. The rest of that energy is lost to vibrations in the semiconductor as heat instead of electrical energy. BUT - here's another area where nanostructured devices might help, because it takes much longer for an energetic electron to emit those vibrations in a structure on the quantum scale (i.e., nanometer scale). These energetic electrons can sometimes be collected at their high energy or kick up another electron across the bandgap through Auger recombination. This has been demonstrated a few times for nanometer-sized semiconductor particles called quantum dots and is called "hot electron capture" or "multiple exciton generation" in the scientific literature.

What I'm trying to say is that nanorod structures have the potential of increasing the maximum efficiency because they might be able to collect those higher energy photons and pull out more electricity than a conventional photovoltaic cell.

Hopefully this will be practical someday...the multijunction cells are just way too expensive how they are currently made.