Infrared absorption and visible transparency in heavily doped p-type BaSn0_3

摘要

The recent experimental work shows that perovskite BaSnO_3 can be heavily doped by K to become a stable p-type semiconductor. Here, we find that p-type perovskite BaSnO_3 retains transparency for visible light while absorbing strongly in the infrared below 1.5 eV. The origin of the remarkable optical transparency even with heavy doping is that the interband transitions that are enabled by empty states at the top of the valence band are concentrated mainly in the energy range from 0.5 to 1.5 eV, i.e., not extending past the near IR. In contrast to n-type, the Burstein-Moss shift is slightly negative, but very small reflecting the heavier valence bands relative to the conduction bands.