Parity nonconservation and bulk photovoltaic effect in a crystal without symmetry center

The theory and the experimental characteristics of the bulk photovoltaic effect in ferroelectric and piezoelectric crystals are considered. This new effect is caused by violation of the principle of detailed balancing for nonthermalized carriers. In conclusion, the new effect of ferroelectric photovoltages on domain walls is considered, as is its potential use in solar energy generation.