Electrical and Optical Properties of Si-SnO₂ Heterojunctions

Abstract

Electrical and optical properties have been investigated on Si–SnO 2 heterojunctions. Semiconducting SnO 2 film has been grown by a successive oxidation of the evaporated tin on the (111) surface of silicon single crystal. The SnO 2 film shows the properties of a degenerate n -type semiconductor having the band gap energy of 3.5 eV. The current-voltage characteristics of Si–SnO 2 n – n heterojunction represent a good rectification. The photovoltage measurements demonstrate that the Si–SnO 2 n – n heterojunction has the photoresponse in the wide wavelength region from 400 to 1200 mµ at room temperature. The energy band diagram of Si–SnO 2 n – n heterojunction is determined from the results of these electrical and optical measurements.