OPTOELECTRONIC COUPLING IN ORGANIC MIS STRUCTURES

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