A nano-LED containing an array of nano-pillars of different diameters that are distributed over an emission area of an LED chip is capable of emitting broadband and white or nearly white light. Since each pillar emits light at a different wavelength according to its diameter and strain state, the overall emission spectral characteristics of the device is a combination of individual spectrum, giving rise to broadband emission. The spectral shape can be tailored for different shades of white emission, by controlling the distribution of the different diameter nano-pillars. The nano-pillars are patterned by nanosphere lithography.