Surface photovoltage imaging for the study of local electronic structure at semiconductor surfaces

Atomically-resolved surface photovoltage (SPV) imaging with a scanning tunnelling microscope was used by several laboratories to reveal the local degree of sub-surface electronic band bending at and around defects and adsorbates on various semiconductor surfaces. It turns out that the scanning tunnelling microscope tip-induced electric field, and/or the charging of surface states by the tunnelling current, can affect the band bending under the tip and help us learn more about the surface local electronic structure. This review features an explanation of the band bending phenomenon and how it gives rise to SPV, SPV imaging methods, a coverage of the experimental work done up to this date, and finally, a discussion about the source of atomically resolved features in the SPV maps.