Crystalline-Oriented Beta-Sialon:Eu 2+ Deposits Fabricated by Electrophoretic Deposition (EPD) within Strong Magnetic Field

Abstract

© 2014 The Electrochemical Society. Electrophoretic deposition (EPD) assisted with a horizontally-setup strong magnetic field (12 T) was utilized to fabricate the deposits of the β-sialon:Eu2+phosphor. The direction of the magnetic field was perpendicular to that of the electric field. The deposits were fabricated by aligning the β-sialon:Eu2+particles along the higher magnetic-susceptibility c-crystal axis (a, b-crystal plane), therefore making the oriented deposits consist of the phosphor particles present dominant appearances of the side faces (a, b-plane). Particularly, longer depositing time gave rise to higher orientation degree. Photoluminescence (PL) intensities of the deposits oriented along a, b-plane were significantly improved by comparing with those of the randomly-oriented samples; especially, the 12.4%-fold improvement of the PL intensity was obtained at 150 s depositing time. This fabrication technique of the oriented phosphor deposit may be potentially used to prepare the flat LEDs, with more brightness, instead of conventional methods.