X-Ray Photoelectron Spectroscopy Surface Analysis Applications

Improving energy storage is crucial for transitioning towards carbon-neutral technologies. Advancements in battery research require a comprehensive understanding of cell materials, necessitating the use of various analytical techniques. Surface analysis, particularly X-ray photoelectron spectroscopy (XPS), is one of the leading methods used. XPS and related surface analysis analytical methods reveal the chemistry of a sample’s outermost atomic layers, which are vital in battery materials such as electrodes or separators due to their contact with the electrolyte and influence on device performance over time. XPS is widely employed in research, development, materials screening, and failure analysis, often in concert with scanning electron microscopy for structural analysis or spectroscopic techniques such as Raman spectroscopy.

Surface chemistry plays a crucial role in the performance of catalysts, and X-ray photoelectron spectroscopy (XPS) has been a valuable tool for assessing both active and support materials. By quantifying the chemical states at the surface, XPS enables the investigation of batch failures and provides insights into changes in catalytic activity throughout the material’s lifecycle.

Precise control of the biological activity of surfaces is becoming increasingly important for applications in biomedical research. Over the years, there has been a focus on modifying the surface chemistry of in-vivo medical devices like stents and joint replacements to ensure stability within the patient and offer additional advantages such as drug elution. These processes are now being expanded to include the use of active nanoparticles for antimicrobial coatings on fabrics and surfaces, as well as improving the comfort of devices like contact lenses. X-ray photoelectron spectroscopy (XPS) has emerged as a crucial technique in the development of such materials.

X-ray photoelectron spectroscopy (XPS) is a standard technique used to identify the root cause of failures resulting from contamination or defects. When the issue resides at the surface or an interface, XPS and XPS depth profiling can be employed to determine the chemical changes responsible for defects or delamination.

Enhancing the efficiency of solar cells is a significant focus of research to facilitate the decarbonization of energy generation. Advanced photovoltaic devices employ intricate material compositions or layer structures to optimize sunlight-to-electricity conversion. XPS, along with complementary techniques like ultraviolet photoelectron spectroscopy (UPS) and reflection electron energy loss spectroscopy (REELS), can be employed in tandem to comprehensively investigate the chemical composition and electronic structure of newly developed solar cell materials.

Thin, transparent coatings are applied to glass surfaces to impart beneficial properties for automotive, architectural, and biological applications. Whether they aim to provide anti-reflective properties or ensure that a drug can be stored safely in a vial, the layers applied to the surface can be quite complex. XPS depth profiling using either monatomic or gas cluster ion sources is an ideal way to verify the correctness of the created layer structure.

Modern semiconductor devices consist of ultra-thin layers deposited on substrates, sometimes doped to refine their performance. Employing techniques such as XPS depth profiling, angle resolved XPS, ISS, UPS, and REELS is crucial for comprehending these layer structures and confirming their integrity. While XPS may lack the spatial resolution to identify features on patterned wafers, surface analysis methods are valuable for assessing bond pad conformity and measuring layered materials like OLEDs or displays.

XPS enables analysts to investigate various surface issues on metal and oxide surfaces. Passivation layers utilized for steel protection can be efficiently investigated using XPS due to their thin nature. Through the measurement of composition and thickness of these protective oxide films on metals, their performance can be understood and adjusted. The chemistry of oxide and metal surfaces holds significance across a wide range of applications, including pigments, catalysis, glass coatings, and biomaterials.

In the past twenty years, XPS has emerged as a key analytical technique for studying polymeric materials, primarily due to advancements in insulator analysis and the introduction of gas cluster ion sources. In addition to elemental and chemical state identification and quantification, as well as detection of organic and inorganic contaminants, XPS now allows for more advanced analysis. Surface uniformity can be investigated, which is crucial when applying surface treatments to achieve specific properties. The use of gas cluster ion sources enables probing of interfacial chemistry by selectively removing surface material and measuring the remaining components without damaging the underlying chemistry, a limitation observed with monatomic ion beams.