  The bulk photovoltaic effect (BPVE) is a phenomenon which creates a net
electrical current from sunlight in a polar noncentrosymmetric material
possessing a moderate band gap. This effect is being explored as an alternative
to traditional pn-junction solar cells to convert solar energy into
electricity. This paper assesses the possibility that hydrogenated Zintl-phase
compounds consisting only of metal, metalloid, and hydrogen atoms, may be able
to provide a BPVE response. Towards this end, the magnitude of the BPVE shift
current is calculated for each of the compounds AeTrTtH (Ae = Ca, Sr, and Ba;
Tr = Al and Ga; and Tt = Si, Ge, and Sn). For this family of hydogenated Zintl
compounds, maximum shift current responses are predicted that are up to eight
times greater than that calculated for BiFeO3, and have a significant response
down to much lower photon energies than BiFeO3 as well. With band gaps below 1
eV, and with some members of this family of compounds exhibiting stability in
air up to 770 K, some of these compounds may find use in photovoltaic devices.

Materials Science;Applied Physics