XPS and electroluminescence studies on SrS1−xSex and ZnS1−xSex thin films deposited by atomic layer deposition technique

Abstract SrS 1− x Se x and ZnS 1− x Se x thin films were deposited by the atomic layer deposition (ALD) technique using elemental selenium as the Se source, thus avoiding use of H 2 Se 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 ZnS 1− x Se x and SrS 1− x Se x were covered with an oxide and carbon-containing contaminants from exposure to air. The oxidation of SrS 1− x Se x extended into the film and peak shifts from sulfate were found on the surface. Luminance measurements showed that emission intensity of the ZnS 1− x Se x :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 SrS 1− x Se x :Ce devices decreased markedly as compared to the SrS:Ce device. Emission colors of the devices were altered only slightly due to selenium addition.