Electric field effect on hybrid exciton states in organic-inorganic quantum wells

Abstract

A new type of excitonic state is considered in a composite organic-inorganic semiconductor nanostructure. Our interest is focused on the mixed exciton formation at the interface in organic (anthracene)-inorganic ( ZnSe ZnCdSe ) quantum wells, in electric fields. The electric field induces spatial separation of electrons and holes in the inorganic quantum wells, leading to a reduction of their binding energy and a shift of the resonance region where Frenkel and Wannier-Mott excitons are strongly mixed. In strong fields, a quadratic Stark shift is found. An important effect is the possibility of using the Stark shift to tune the resonance between Frenkel and Wannier excitons. This fact is very important from a practical point of view because it may be difficult to grow such a structure exactly at resonance.