Solid state light sources based on compound semiconductors are opening a new era in general lighting and will contribute significantly to a sustainable energy saving. For a successful and broad penetration of LEDs into the general lighting market two key factors are required: high efficiency and low cost. Two new disruptive technologies based on nanostructured semiconductors are proposed to address these key factors. A novel epitaxial growth technique based on nanorod coalescence will be explored to realize ultra-low defect density templates which will enable strain-relieved growth of LEDs and thus achieve higher efficiency. The second highly innovative approach is the growth of directly emitting Gallium nitride based nanorod structures. These structures are expected to produce exceptionally high efficiency devices covering the whole visible spectrum and even phosphor-free white LEDs. Significantly, our new nanostructured compound semiconductor based technology will enable LED growth on low-cost and large-area substrates (e.g., Silicon) as wafer bowing will be eliminated and thus lead to a dramatic reduction in production costs. The main objectives over the three years are: •Profound understanding of the growth mechanisms and properties of nanorod systems •New materials and process technologies (wafer-scale nanoimprinting, dry etching, device processing) for LEDs based on nanostructured templates and nanorod-LEDs •Demonstrators: -Phosphor-converted white LEDs based on nanostructured sapphire templates (efficacy ≥ 150 lm/W @ 350 mA) and Silicon templates (efficacy ≥ 100 lm/W @ 350 mA) -Blue, green, yellow and red emitting Nano-LEDs (external quantum efficiency ≥ 10%) -Novel phosphor-free white-emitting Nano-LEDs (external quantum efficiency ≥ 2%) Realising the objectives of SMASH will start a new generation of affordable, energy-efficient solid state light sources for the general lighting market and will push the LED lamp and luminaire business in Europe.