An electrically injected AlGaN nanowire defect-free photonic crystal ultraviolet laser

We report on the demonstration of an electrically injected AlGaN nanowire photonic crystal laser that can operate in the ultraviolet spectral range. The nanowire heterostructures were grown on sapphire substrate using a site-controlled selective area growth process. By exploiting the topological high-Q resonance of a defect-free nanowire photonic crystal, we have demonstrated electrically pumped lasers that can operate at 369.5 nm with a relatively low threshold current density of ~2.1 kA/cm 2 under continuous wave operation at room-temperature. This work provides a promising approach for achieving low threshold semiconductor laser diodes operating in the UV spectral range that were previously difficult.