Growth of samarium monosulfide thin films by co-sputtering deposition

Thin films of SmS, either the semiconductor phase (S-SmS) or the metal one (M-SmS) stable at atmospheric pressure, were grown for the first time by co-sputtering of a Sm2S3 compound target and a Sm metal target in Ar discharge. The reactive species (sulfur) was self-provided in a controllable way from the dissociation of Sm2S3 during sputtering, thus minimizing the conventional use of toxic H2S or contaminative solid sources. X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and spectrophotometry were employed in film characterization. Stoichiometric S-SmS films were formed by optimizing the power ratio applied to the two targets, and M-SmS films were directly obtained by slightly enriching the film with Sm. The films were dense with little impurity. The S-SmS and M-SmS films differ substantially in optical properties from the visible region to the IR. (C) 1998 Elsevier Science B.V. All rights reserved.