Like Aledia, NS Nanotech is developing nanowires. CEO Seth Coe-Sullivan noted that being able to grow red, green and blue nanowires in a single epitaxy step is a big deal since the color is determined by the diameter of the nanowire. The same amount of indium is hitting the RGB nanowires, but different amounts are “sticking” to the nanowires, thus determining the color.

He argued that no matter the size of the sub-pixel, the nanowires will always be wired in parallel. This should mean that there should be no difference in the EQE if the sub-pixel is 100 microns or 1 micron. In the chart below, the left graph shows how EQE falls off with sub-pixel size for the conventional top-down processing but is essentially flat with bottom-up processing.

Coe-Sullivan also made the point that over two orders of current density there is no wavelength shift at all. That’s not true for any semiconductor. In the nanowires design, the idea is to overlap the semiconductor bandgap wavelength with the photonic bandgap so that they amplify the emission. Finally, he showed that in collaborative work with the University of Michigan, they can now achieve EQE of 12% for red with 5×5 micron pixels which is stable in wavelength and EQE over several orders of magnitude.