SrS1-xSex and ZnS1-xSex thin films were deposited by the atomic layer deposition (ALD) technique using elemental selenium as the Se source, thus avoiding use of H2Se or organometallic selenium compounds. X-ray diffraction (XRD) analysis showed that the films were solid solutions and X-ray photoelectron spectroscopy (XPS) data showed that the surface of both ZnS1-xSex and SrS1-xSex were covered with an oxide and carbon-containing contaminants from exposure to air. The oxidation of SrS1-xSex extended into the film and peak shifts from sulfate were found on the surface. Luminance measurements showed that emission intensity of the ZnS1-xSex:Mn alternating current thin film electroluminescent (ACTFEL) devices at fixed voltage was almost the same as that of the ZnS:Mn device, while emission intensity of the SrS1-xSex:Ce devices decreased markedly as compared to the SrS:Ce device. Emission colors of the devices were altered only slightly due to selenium addition. (C) 2003 Elsevier B.V. All rights reserved.