Papers by Author: J. Piqueras

Abstract: Sintering of a ZnO-MgO powder mixture under argon flow leads to the growth of elongated Mg doped ZnO structures such as stacks of nanoplates and rods with secondary nanowires in a comb-like arrangement. The nanoplates grow perpendicular to a central axis and have a six-fold symmetry. The hierarchical growth is related to the presence of Mg. Cathodoluminescence (CL) in the scanning electron microscope shows a blue-shift of the ZnO exciton peak as well as changes in the deep level bands due to the influence of Mg.

Abstract: In this work we present results of Si/SiO2/SiON/SiO2 waveguides fabricated by means of ECR-PECVD. In order to change refraction index and simultaneously to reduce losses related with hydrogen, we have used N2 as precursor gas for controlling the nitrogen to oxygen relation present in the samples. The composition of the samples were carefully controlled by RBS and ERDA analysis. The refractive index and thickness were measured by using a prisma coupler method at a wavelength of 632.8 nm.