Solution-processed nanographene distributed feedback lasers.

The chemical synthesis of nanographene molecules constitutes the bottom-up approach toward graphene, simultaneously providing rational chemical design, structure-property control and exploitation of their semiconducting and luminescence properties. Here, we report nanographene-based lasers from three zigzag-edged polycyclic aromatics. The devices consist of a passive polymer film hosting the nanographenes and a top-layer polymeric distributed feedback resonator. Both the active material and the laser resonator are processed from solution, key for the purpose of obtaining low-cost devices with mechanical flexibility. The prepared lasers show narrow linewidth ( < 0.13 nm) emission at different spectral regions covering a large segment of the visible spectrum, and up to the vicinity of the near-infrared. They show outstandingly long operational lifetimes (above 10 pump pulses) and very low thresholds. These results represent a significant step forward in the field of graphene and broaden its versatility in low-cost devices implying light emission, such as lasers.