摘要: At an electrified interface the double-layer problem plays a key role. Its characteristics for ionic liquids are discussed on basis of recent experimental and theoretical investigations contrasted with classical GCS model aqueous electrolytes. Emphasis this chapter is 2D 3D electrochemical phase formation growth at liquid/electrode studied by in situ scanning probe methods. The concept underpotential (UPD) deposition briefly introduced example Ag UPD Au(111) different behaviour liquid electrolytes described. Phenomena surface alloying underlying spinodal mechanism treated more detail. characteristic structures their evolution during Zn − Cd presented. Nanoscale metal semiconductor clusters from topic last section. Selected examples Al electrodeposition Si(111):H, Ni, Fe nanocrystal growth; Co bulk alloying; AlSb ZnSb compound deposition. ends thickness induced metal–nonmetal transition ultrathin Ge films electrodeposited or Si(111):H.