Figure 3.

a Room temperature EL spectra of ZnO/GaN LEDs under forward bias from nanotubes (blue) and nanorods (red). Digital images of the LED devices taken at the same applied voltage from b ZnO nanotubes c ZnO nanorods

Sadaf et al. Nanoscale Research Letters 2010 5:957-960   doi:10.1007/s11671-010-9588-z