Interfacial and rectifying characteristic of epitaxial SrTiO3-δ/GaAs p–n junctions

Oxygen-deficient SrTiO3-δ thin films were grown on p-GaAs substrates to form p–n heterojunctions. The interfacial and transport characteristics of the heterojunctions have been investigated. The sharp interface was found to be epitaxially crystallized. The junctions present good rectifying behaviors and thickness dependence of current–voltage properties. The electronic transport of 200 nm thick SrTiO3-δ/GaAs could be explained by a space charge limited model. When the thickness was reduced further, the diode ideality factors were almost temperature independent, which might be attributed to a strain-assisted tunneling mechanism.