Electric-field-induced modification of the optical properties of CuI crystals

The study is concerned with the effect of a dc electric field applied to copper iodide crystals on the resistivity of the crystals and their transparency and luminescence in the visible and ultraviolet spectral regions. It is shown that the conductivity, transparency, and edge luminescence intensity of the crystals decrease upon application of an electric field at room temperature with characteristic times of about 10 min. The reversibility of these processes, associated with the formation and diffusion of donor- and acceptor-type intrinsic defects (Cu$_i$ and $V_{\mathrm{Cu}}$) in the crystal lattice of the CuI compound, is established.