https://doi.org/10.1351/goldbook.14004
Subsurface space where the majority carriers are forced away owing to band bending caused by the surface potential. (i) The subsurface layer of an n-type semiconductor becomes depleted of electrons, which are the majority carriers, as a consequence of upward band bending. (ii) The subsurface layer of a p-type semiconductor becomes enriched by electrons (depleted of holes) as a consequence of downward band bending.
Note: The surface charge sign is identical to the sign of the majority charge carriers. The surface charge (surface potential) in semiconductors is produced as a result of adsorption or contact with the medium (an electrolyte or another surface).
See: inversion layer