ELECTRIC-FIELD EFFECT ON HYBRID EXCITON-STATES IN ORGANIC-INORGANIC QUANTUM-WELLS

A new type of excitonic state is considered in a composite organic-ino rganic semiconductor nanostructure. Our interest is focused on the mix ed exciton formation at the interface in organic (anthracene)-inorgani c (ZnSe/ZnCdSe) quantum wells, in electric fields. The electric field induces spatial separation of electrons and holes in the inorganic qua ntum well, leading to a reduction of their binding energy and a shift of the resonance region where Frenkel and Wannier-Mott excitons are st rongly mixed. In strong fields, a quadratic Stark shift is found. An i mportant effect is the possibility of using the Stark shift to tune th e resonance between Frenkel and Wannier excitons. This fact is very im portant from a practical point of view because it may be difficult to grow such a structure exactly at resonance. (C) 1997 Elsevier Science B.V.