Relationship between structure and luminiscent properties of epitaxial grown y₂O₃:Eu thin films on LaAlO₃ substrates

Cathodoluminescence images of individual pores have been obtained at nanometer resolution in europium-activated yttrium oxide (Y₂O₃:Eu) (001) thin films, epitaxially grown on LaAlO₃ (001) substrates. Comparison with Z-contrast images, obtained simultaneously, directly show the "dead layer" to be about 5 nm thick. This "dead layer" is the origin of the reduced emission efficiency with increasing pore size. Pore sizes were varied by using different substrate temperatures and laser pulse repetition rates during film growth. These films are epitaxially aligned with the substrate, which is always Al terminated.