ANOMALOUS STARK-EFFECT ON EXCITONIC STATES IN A PREIONIZATION ELECTRIC-FIELD

The low-temperature (T = 80 K) excitonic light reflection spectra of C dS crystals in the electric field of a Schottky barrier are investigat ed. An anomalous Stark shift of the hydrogen-like excitonic state in t he preionization limit is recorded for the first time. The distributio n of the subbarrier electric field is determined from an analysis of t he spectra performed on the basis of the theory of nonlocal dielectric response in a spatially inhomogeneous medium. (C) 1996 American Insti tute of Physics.