Electronic states at conducting polymer conducting oxide interfaces observed using a low-energy photoelectron spectroscopic method

We have observed the electronic states at conducting polymer/conducting oxi de interfaces using a low-energy photoelectron spectroscopic method. The el ectronic states of conducting polymer/indium tin oxide (ITO) interfaces wer e different from those of conducting polymer/metal interfaces. The electron transfer from a conducting polymer to ITO occurred at the interfaces, and is not related to the difference of the ionization potential between conduc ting polymers and ITO. Although the origin of this electron transfer is not clear at this stage, we speculate that the surface states of ITO play a ma jor role. Moreover, the electron transfer at the interfaces is enhanced at higher temperatures. Other conducting oxides such as indium oxide (In2O3) a nd tin oxide (SnO2) also show a similar tendency to that of ITO. (C) 1999 A merican Institute of Physics. [S0003-6951(99)01928-2].