Light-emitting-diodes (LEDs) are used in numerous electronics and have many advantages over other light sources. Such as lower energy consumption, longer lifetime, and smaller size. Bae and coworkers have successfully made GaAs NW array based LED on Si.\cite{Bae_2014} The LED could emit light at a peak wave length of \(\lambda\) = 830 nm. The method of fabrication was unique because no chemical lithography was involved for the patterning process but instead a SiO\(_2\) hole pattern is created by self assembled InAs NW as a mask. The lithography free method of fabrication could allow for large scale and low cost production of LEDs.
GaAs core and AlGaAs shell NWs are used in LED fabrication as well. Tomioka and coworkers integrate GaAs NW-based LEDs on Si substrate by selective-area metalorganic vapor phase epitaxy.\cite{Tomioka_2010} Strong electroluminescence emissions were observed from the NWs directly grown on Si, which had a threshold current of 0.5 mA at 1.9 V. The electroluminescence intensity increased superlinearly with current injection and saturated with further increased current injection.\cite{Tomioka_2010}