OPTOELECTRONIC COUPLING IN ORGANIC MIS ST RUCTURES

The particular optical properties of charge carriers in organic semico nductors are at the origin of new coupling effects between electronic and optical properties, as exemplified by the changes in optical absor ption induced by charge injection within Metal-Insulator-Semiconductor (MIS) structures. By combining such effects with photoconducting prop erties, what we have done by using an oligoparaphenylene ethenylene th in film ad the semiconductor and an aluminum injection electrode, the charge injection must be assisted by an excitation light. Such techniq ues revealed as a powerfull tool for in situ optical characterisation of electronic properties of such materials. Moreover, we have thus dem onstrated a new type of photochromic device, with electrically control ed time constant and erasure.