X-ray Photoelectron Spectroscopy (XPS)
X-ray photoelectron spectroscopy (XPS) is a highly surface-specific chemical analytical technique used to probe the elemental composition and bonding states in the outermost 2-10 nm of a solid surface. To characterize composition as a function of penetration depth in the sample, depth-profiling tests can be performed to iteratively access sub-surface compositional layers.