Pintapotentiaalia

Pintapotentiaalia, in Finnish often rendered as surface potential in English, is the electric potential at and near an interface between two phases, most commonly a solid surface and a liquid or vacuum. It arises from the arrangement of charges at the surface, including surface dipoles, adsorbates, and the formation of an electrical double layer in electrolytic environments. In solid–gas or solid–vacuum interfaces, pintapotentiaalia reflects the alignment of electronic states at the surface and is related to the work function; in liquid environments it is shaped by the distribution of ions near the interface and, at the nanoscale, by band bending and surface states in semiconductors.

The physical picture combines electrostatics and interfacial chemistry. Surface charges produce an electric field that extends into adjacent phases, giving rise to a measurable potential difference. This potential influences charge transfer, adsorption processes, and chemical reactivity at the interface. In semiconductors, surface potential can change with illumination, bias, or chemical environment, affecting device performance. The term is often used interchangeably with “surface electrostatic potential,” though in some contexts it is distinguished from the overall electrochemical potential that includes chemical potential terms.

Measurement and determination methods include non-contact techniques such as Kelvin probe and Kelvin probe force microscopy, which measure contact potential differences between a reference probe and the sample. In liquids, electrokinetic methods relate surface potential to zeta potential through models of the electrical double layer. Scanning probe and electrochemical impedance techniques can map or infer surface-potential distributions. Pintapotentiaalia thus serves as a key parameter in surface science, influencing phenomena from corrosion and catalysis to electronic and optoelectronic device interfaces.