Molecular beam epitaxy of single-crystalline aluminum film for low threshold ultraviolet plasmonic nanolasers

High-quality single-crystalline aluminum films have been grown on Si(111) substrates by molecular beam epitaxy. The x-ray diffraction rocking curve of the (111) plane of the Al film shows a full width at half maximum of 564 arc sec for the sample grown at 100 degrees C, where the surface is atomically flat with a root-mean-square roughness of 0.40 nm in a scanned area of 3 X 3 mu m(2). By using such a high-quality Al film, we have demonstrated a room temperature ultraviolet surface-plasmon-polariton nanolaser at a wavelength of 360 nm with a threshold as low as similar to 0.2MW/cm(2), which provides a powerful evidence for potential application of the single-crystalline Al film in plasmonic devices. Published by AIP Publishing.