CONJUGATED POLYMER SURFACES AND INTERFACES - A MINIREVIEW AND SOME NEW RESULTS

Since the discovery of high electrical conductivity in doped polyacety lene in 1977, conjugated polymers have emerged as viable semiconductin g electronic materials for numerous applications. In the context of po lymer electronic devices, it is of critical importance to understand t he nature of the electronic structure of the polymer surface and the i nterface with metals. It has been shown that, especially for conjugate d polymers, photoelectron spectroscopy provides a maximum amount of bo th chemical and electronic structural information in one (type of) mea surement. An overview of some details of the early stages of interface formation with metals on the surfaces of conjugated polymers and mode l molecular solids, especially in connection with polymer-based light- emitting diode (LED) devices, was presented at the symposium for Alan Heeger. Materials involved include poly(p-phenylenevinylene) (PPV), as well as a series of substituted PPVs, and a diphenylpolyene molecule, namely alpha,omega-diphenyltetradecaheptaene. Some general trends in the behavior of light-metal atoms on the clean surfaces of conjugated polymers was pointed out. Here, the core details of the oral presentat ion will be outlined. In addition, some new results presented are disc ussed, briefly, in order to indicate some recent new developments in t his area. Finally, some details of one specific new issue are reviewed in slightly more detail. The choice of new results presented is influ enced by recent publications by Alan Heeger and friends at Santa Barba ra.