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Multilayered thermoelectric Sn/Sn+SnO2 thin films were prepared using KJL DC/RF magnetron sputtering system under Ar gas plasma on the SiO2 substrates. The thicknesses of the fabricated thin films were found using Filmetrics UV thickness measurement system. The fabricated thin films were annealed at different temperatures for one hour to tailor the thermoelectric properties. In this study, unannealed, annealed at 150 and 300 °C samples were characterized using Thermo Fisher XPS system brought to the Alabama A&M University by the NSF-MRI support. X-ray Photoelectron Spectroscopy (XPS), also known as Electron Spectroscopy for Chemical Analysis (ESCA) is a type of analysis used for characterization of various surface materials. XPS is mostly known for the characterization of thin films - which are coatings that have been deposited onto a substrate and may be comprised of many different materials to alter or enhance the substrate’s performance. XPS analysis provides information for composition, chemical states, depth profile, imaging and thickness of thin film. This paper focuses on the application of XPS techniques in thin film research for Sn/Sn+SnO2 multilayered thermoelectric system and SiO2 substrates annealed at different temperatures. Since SiO2 substrates were used during the deposition of the multilayer thin films, we would like to perform detailed XPS studies on the SiO2 substrates. SiO2 substrates is being used with many researchers, this manuscript will be good reference for the researchers using SiO2 substrates. Thermal treatment of the substrates and the multilayered thin films has caused some changes of the XPS characterization including binding energy, depth profile, peak value and FWHM. The treatment effects were discussed and compared to each other. 

High-resistivity zinc cadmium telluride (CdZnTe) semiconductor is a very popular material for room-temperature nuclear detection applications. It is used for the detection of X-rays and gamma rays in many areas: nuclear and radiological threat detection, medical imaging, gamma spectroscopy, and astrophysics. Mechanical stability at the interface of electrical contacts and the detector material is an important factor in terms of durability and shelf life of detector devices. Other engineering factors where that interface plays an important role include thermal expansion due to temperature changes and vibrations that may result from certain applications. The surface composition of the material play an important role in the surface stability of the material. The stoichiometric composition of the detector surfaces also affects its surface current, which, in turn, contributes to electronic noise. High electronic noise is detrimental to the energy resolution of the detector device. X-ray photoelectron spectroscopy (XPS) is a good technique for determining dominant surface composition of materials. In this current study, the authors used an XPS to look at the dominant composition materials on the surface of a CdZnTe wafer. The experiments involved loading CdZnTe wafers into the XPS machine and recording the peaks of the binding energies of elements and compounds present on the surfaces. The XPS results showed the presence of Zn, Te, O, Cd, C, Cl, Si, and TeO2. These results are important in the engineering of CdZnTe radiation detection devices. 

Cadmium manganese telluride (CdMnTe) crystals are expected to be homogeneous in structure due to the segregation coefficient of Mn in CdTe, which is about 1.0. This could translate in the growth of large-volume CdMnTe crystals free of defects that currently limit X-ray and gamma-ray detection efficiencies. The present characterization experiments show results on CdMnTe planar detectors grown by the vertical Bridgman technique. The CdMnTe crystal used in the experiments was mostly free of tellurium inclusions and high angle grain boundaries. We recorded an energy resolution of 9.2% FWHM for the 59.5-keV gamma-peak of Am-241 for the planar detector. We also resolved peaks at energies below the 59.5-keV peak.