Complex sentence: This process is employed in a spectroscopy technique formally known as ARPS-- "Angle Resolved Photoelectron Spectroscopy"--which is used to investigate the electronic structure of solids, solid surfaces and interfaces.
Split into simpler sentences: This process is employed in a spectroscopy technique formally known as ARPS-- "Angle Resolved Photoelectron Spectroscopy" --. ARPS is used to investigate the electronic structure of solids, solid surfaces and interfaces.