The smart folks over at Philips nanotechnology research have been growing indium phosphide (InP) nanowires. One of thier hopes is that the one-dimensional structure will eventually allow greater efficiencies. The nanowires are grown, unlike the etching processes that are used to make conventional LEDs.

For a nice overview of the process of growing these tiny guys, check out this small brochure [pdf] that describes the process with some nice diagrams and microscope pictures.