Comparative Study of the Lateral Photovoltaic Effect in Fe3O4/SiO2/n-Si and Fe3O4/SiO2/p-Si Structures

Resumo

The results of a comparative study of the lateral photovoltaic effect in Fe₃O₄/SiO₂/n-Si and Fe₃O₄/SiO₂/p-Si structures are presented. The lateral photovoltage reaches its maximum near the measurement contacts in both structures, but the signs of this voltage differ. As the light spot moves away from the contacts, the photovoltage varies linearly in Fe₃O₄/SiO₂/n-Si and decreases exponentially in Fe₃O₄/SiO₂/p-Si. It is found that interface states at the SiO₂/Si interface induce the photovoltage polarity inversion associated with a change in the conductivity type of silicon. An extreme thickness dependence of the photovoltage with an optimum Fe₃O₄ film thickness of ~50 nm is observed in both structures.