Features of the band structure and the mechanism of lateral photoconductivity in hybrid structures $T$/SiO$_2$/Si ($T$ = Fe, Fe$_3$O$_4$, TiO$_2$)

This paper presents the results of studying the lateral photovoltaic effect in hybrid structures based on SiO$_2$/Si depending on the nature of the conductivity of the material of the upper layer (Fe is a metal, Fe$_3$O$_4$ is a semimetal, TiO$_2$ is a semi-insulator). It is shown that this effect is observed in hybrid structures in which a depleted region with a significant band bending is formed at the SiO$_2$/Si interface. Theoretical calculations of the lateral photovoltage based on the energy parameters of the band diagrams showed that an increase in the sensitivity of the lateral photoelectric effect is associated with an increase in the built-in potential at the SiO$_2$/Si interface. It has been established that the transient characteristics of the lateral photoelectric effect, such as the rise and fall times of the photovoltage signal, are determined by the configuration of the RC-filter in the near-contact region, which depends on the conductivity of the upper layer. It is shown that, in the case of the lateral photovoltaic effect, current transfer occurs along the inversion layer, and the upper layer serves to generate a quasi-$p$–$n$ junction at the SiO$_2$/Si interface.