Self-assembled island formation of LiNbO by pulsed laser 3 deposition on a-Al O substrate

LiNbO3 0001.films were grown epitaxially on a-Al2O3 0001.substrate by pulsed laser deposition PLD.. The initial growth of LiNbO3film on atomically flat sapphire a-Al2O3.substrates has been investigated by atomic force microscopy AFM.and X-ray photoelectron spectroscopy XPS.. The two-dimensional LiNbO3 layer with thickness of about 1 nm was formed before three-dimensional growth occurred. Subsequently grown islands were distributed uniformly on the terrace surface. This result indicates that the LiNbO3 grows in the Stranski–Krastanov growth mode. Judging from X-ray 2u–u diffraction XRD.and reflection high-energy electron diffraction RHEED.patterns, high quality epitaxial film was obtained. And, the film emitted visible photoluminescence PL.at room temperature. q1998 Elsevier Science B.V.