The Experimental Investigation of the Photovoltaic Effect in Some Crystals without a Center of Symmetry

The photovoltaic effect in some crystals without a center of symmetry (ZnO, α-HgS, and α-quartz) is investigated. It is shown that the impurity centers of different nature give a different contribution to the photovoltaic effect. The influence of the optical recharging of the impurity centers on the spectral distribution and on the kinetics of the photovoltaic effect is noted. The optical activity strongly influences the angular dependence of the photovoltaic current, observed in the linearly polarized light.