Document Type

Article

Publication Date

1-27-2025

Keywords

photogalvanic effect, shift current, materialsdesign, superlattices, BiFeO3

Abstract

Designing materials with a controlled photovoltaic response may lead to improved solar cells or photosensors. In this regard, ferroelectric superlattices have emerged as a rich platform to engineer functional properties. In addition, ferroelectrics are naturally endowed with a bulk photovoltaic response stemming from nonthermalized photoexcited carriers, which can overcome the fundamental limits of current solar cells. Yet, their photovoltaic output has been limited by poor optical absorption and poor charge collection or photoexcited carrier mean free path. We use Density Functional Theory and Wannierization to compute the so-called Bulk Photovoltaic shift current and the optical properties of BiFeO3/LaFeO3 superlattices. We show that, by stacking these two materials, not only the optical absorption is improved at larger wavelengths (due to LaFeO3 smaller bandgap) but also the photogalvanic shift current is enhanced compared to that of pure BiFeO3, by suppressing the destructive interferences occurring between different wavelengths.

Comments

Web of Science

ACS

Included in

Physics Commons

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