Tailoring the photovoltaic effect in (111) oriented BiFeO3/LaFeO3 superlattices

TL;DR

This study explores how the photovoltaic effect in BiFeO3/LaFeO3 superlattices can be tuned by adjusting composition and phase transitions, revealing switchable and non-switchable photovoltaic behaviors linked to ferroelectric states.

Contribution

It demonstrates the modulation of photovoltaic response in superlattices through controlled ferroelectric to paraelectric phase transitions and associated conduction mechanisms.

Findings

High BiFeO3 concentration yields switchable photovoltaic response.

Certain LaFeO3 concentrations lead to non-switchable photovoltaic effects.

Transition from bulk-limited to interface-limited conduction mechanisms observed.

Abstract

Ferroelectric and photovoltaic properties of BiFeO3/LaFeO3 superlattices grown by pulsed laser deposition have been investigated being the bilayer thickness). For a high concentration of BiFeO3 a ferroelectric state is observed simultaneously with a switchable photovoltaic response. In contrast for certain concentration of LaFeO3 a non-switchable photovoltaic effect is evidenced. Such modulation of the PV response in the superlattices is attributed to the ferroelectric to paraelectric phase transition which is controlled with the increase of x. Remarkably, concomitant to this change of PV mechanism, a change of the conduction mechanism also seems to take place from a bulk-limited to an interface-limited transport as x increases.