Optical properties of multilayer Er-doped Ga1As39S60 chalcogenide glass thin films deposited by spin coating

In order to produce spin-coated chalcogenide glass thin films with higher thickness and lower residual solvent, multilayer lamination of 0.85 at.% Er-doped Ga1As39S60 chalcogenide glass was studied. Er was doped into the Ga1As39S60 glass by melt quenching technique. Solutions for spin coating were prepared from glass powders dissolved in propylamine at a concentration of 0.2 gr/ml. Films with 1–4 layers were spin coated using multiply deposition/two step thermal stabilization procedure. The average thickness for each layer was about 0.48 μm as the 4-layered sample was 1.76 μm thick. Influence of multilayer lamination on optical parameters of films and the amount of residual solvent was studied by examining UV visible infrared spectroscopy. According to AFM images, surface roughness of layers decreased with increasing number of layers from 3.6 nm to 0.78 nm. No interfaces were observed from SEM images of multi layered cross section. Although all of the films demonstrated PL emission at 1.55 μm, emission slightly decreased with increasing the number of layers.