Photoluminescence properties of erbium‐doped amorphous gallium‐germanium‐selenium films fabricated by RF sputtering

Abstract

AbstractChalcogenide glasses have various useful features for optical devices such as a high refractive index, low‐loss transmission in the mid‐IR, and low phonon energies. The fabrication of thin films is important for use in waveguide applications and integrated photonics. In this work, we report the properties of vacuum deposited films of gallium‐germanium‐selenium glasses onto fused silica substrates by an RF magnetron sputtering technique (RF electric power of 40‐250 W and growth rate of 0.01‐2.1 μm/min). The concentration of Er3+ ions is controlled by the number of sintered Er2S3 small plates on a target. Samples are shown to be in an amorphous‐like state as measured by X‐ray diffraction experiments. Film thicknesses are proportional to the RF sputtering power and sputtering time. The compositions of films obtained from energy dispersive X‐ray (EDX) analysis. There are much dependent on the condition of the sputtering target, for example whether the target is in the bulk or powder‐state. Photoluminescence (PL) spectrum, intensity, and lifetime at 1550 nm band are measured by excitation from a 973 nm laser. The PL band of the films has a similar shape to those of bulk glasses. The PL intensity increased with the RF electric power. The PL lifetime at the 1550 nm band of the film is about 1.8‐2.6 ms; the latter values are similar to those of bulk samples. The results show that the RF sputtering is a potential method of fabrication for Er‐doped GeGaSe thin films. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)