Abstract :
There has been no consensus on whether the electro-absorption spectrum for molecular crystals depends on the external electric field, the macroscopic electric field, or the local electric field. From a prior rigorous theory of the Stark effect valid for pure and doped crystals, it is shown that in a pure crystal the contribution of the quadratic Stark effect to the electro-absorption spectrum is bilinear in the macroscopic and local fields, but in a doped crystal with localized states it may be quadratic in the local field. In either case, the contribution of the linear Stark effect depends only on the local field.
