Internal bend, adsorbed molecules

Internal Bend (Figures 4c and 5b). The internal modes are used to identify the adsorbed species, and a comparison with the isolated molecule values indicates to what extent the molecule is affected by the surface. 

Some of the molecules that are adsorbed on surfaces (especially oxygen and water) strongly interact with the polymer, so chemical reactions can occur at the interface [66], Surface states are formed that can also cause band bending at this interface region and therefore affect the internal electric field [75]. This interface layer seems to hinder the diffusion of gases and metal atoms further into the polymer and the subsequent chemical reaction of the electrode material with the polymer and can therefore be quite important for the operation of the EL devices [76]. The diffusion of the oxygen from the electrode into the polymer that was observed for ITO devices [77] can also be prevented by introducing a thin layer of polyaniline [78]. For real systems the metal/ polymer junction can therefore be understood as an M.v polymer structure, where. v represents an interfacial layer of currently undefined nature. 

---