In-situ doping of erbium in hydrogenated amorphous carbon by low temperature metalorganic radio frequency plasma enhanced chemical vapor deposition

Abstract

A significant improvement in the photoluminescence of erbium doped amorphous carbon (a-C: H(Er)) is reported. The effects of the RF power on the anode and cathode a-C: H films were investigated in terms of the microstructural and local bonding features. It was determined that Er doped a-C: H films should be placed on the anode to obtain wider bandgap and lower percentage of sp(2) carbon bonding. The metalorganic compound, tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) Erbium(+III) or Er(fod)(3), was incorporated in-situ into an a-C: H host by metalorganic rf plasma enhanced chemical vapor deposition. This technique provides the capability of doping Er in a vertically uniform profile. The high erbium concentration (3.9 at.%), partial fluorination of the surrounding ligands, and the large optical bandgap of the host a-C: H are the primary factors that enable enhancement of the photoluminescence. (C) 2014 Elsevier B. V. All rights reserved.