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.
@article{arxiv.1301.1314,
title = {Oxide Heterostructures for Efficient Solar Cells},
author = {Elias Assmann and Peter Blaha and Robert Laskowski and Karsten Held and Satoshi Okamoto and Giorgio Sangiovanni},
journal= {arXiv preprint arXiv:1301.1314},
year = {2013}
}
Comments
5 pages, 5 figures main paper + 3 pages, 3 figures supplemental information; as published