Oxide Heterostructures for Efficient Solar Cells

TL;DR

This paper explores the potential of transition-metal oxide heterostructures, specifically LaVO_3 on SrTiO_3, for high-efficiency solar cells due to their favorable band gap and internal potential gradient, demonstrated via density-functional theory.

Contribution

It introduces oxide heterostructures as a novel class of materials for solar cells and shows their advantages through theoretical modeling.

Findings

LaVO_3/SrTiO_3 has a direct band gap ~1.1 eV.

Oxide heterostructures have an internal potential gradient aiding charge separation.

Combining LaVO_3 with LaFeO_3 can enhance efficiency through band-gap grading.

Abstract

We propose an unexplored class of absorbing materials for high-efficiency solar cells: heterostructures of transition-metal oxides. In particular, LaVO_3 grown on SrTiO_3 has a direct band gap ~1.1 eV in the optimal range as well as an internal potential gradient, which can greatly help to separate the photo-generated electron-hole pairs. Furthermore, oxide heterostructures afford the flexibility to combine LaVO_3 with other materials such as LaFeO_3 in order to achieve even higher efficiencies with band-gap graded solar cells. We use density-functional theory to demonstrate these features.