Illumination controlled S-shaped current-voltage characteristics of p+-nSi-ITO structures

Abstract Silicon p + n-insulator-ITO structures have been obtained by the deposition of a thin layer of In 2 O 3 :SnO 2 ((ITO) on the n-region of a silicon p-n junction by a spray method. The two-terminal structure shows S-shaped negative resistance I–V characteristics similar to long-base diodes, thyristors and other switching devices. The switching is controlled by optical illumination, but unlike other S-shaped devices, in our case the light switches the structure from high-resistance to the low-resistance state. A band diagram for the investigated structure has been proposed. This diagram allows one to explain the observed current switching as a result of double injection in the nSi region, which became difficult under illumination.