X‑Ray Photoelectron Spectroscopy (XPS) Market Overview X‑Ray Photoelectron Spectroscopy (XPS)—also known as Electron Spectroscopy for Chemical Analysis (ESCA)—is an analytical technique used to determine surface chemistry and elemental composition of materials. It functions by irradiating a material with X‑rays and measuring the kinetic energy of emitted electrons. XPS is widely...