Hexagonal Rare-Earth Manganites as Promising Photovoltaics and Light Polarizers

TL;DR

This study uses first-principles calculations to reveal that hexagonal rare-earth manganites, especially h-TbMnO$_3$, are highly efficient photovoltaic materials with exceptional optical anisotropy, making them promising for solar energy and light polarization applications.

Contribution

The paper demonstrates, through density-functional theory, that hexagonal rare-earth manganites have high photovoltaic efficiency and remarkable optical anisotropy, highlighting their potential in solar cells and light polarizers.

Findings

Maximum light-to-electricity efficiency up to 33% predicted.

Strong light absorption in the solar spectrum range.

Exceptional optical linear dichroism and birefringence predicted.

Abstract

Ferroelectric materials possess a spontaneous electric polarization and may be utilized in various technological applications ranging from non-volatile memories to solar cells and light polarizers. Recently, hexagonal rare-earth manganites, h-RMnO$_3$ (R is a rare-earth ion) have attracted considerable interest due to their intricate multiferroic properties and improper ferroelectricity characterized by a sizable remnant polarization and high Curie temperature. Here, we demonstrate that these compounds can serve as very efficient photovoltaic materials and, in addition, possess remarkable optical anisotropy properties. Using first-principles methods based on density-functional theory and considering h-TbMnO$_3$ as a representative manganite, we predict a strong light absorption of this material in the solar spectrum range, resulting in the maximum light-to-electricity energy conversion efficiency up to 33%. We also predict an extraordinary optical linear dichroism and linear birefringence properties of h-TbMnO$_3$ in a broad range of optical frequencies. These results uncover the unexplored potential of hexagonal rare-earth manganites to serve as photovoltaics in solar cells and as absorptive and birefringent light polarizers.