A FEW-MONOLAYER ORGANIC PHOTODIODE

A few-monolayer zwitterionic, noncentrosymmetric Langmuir-Blodgett fil m has been sandwiched between two electrodes, one of which is transpar ent. Curves of dark current density as a function of applied bias were observed to exhibit rectifier-like behaviour and to follow closely th e dependences measured from junctions using two metallic electrodes. T he transparent indium tin oxide (ITO) electrode discussed here permitt ed illumination of the organic film during electrical characterisation and it was observed that the electrical behaviour was altered from th e dark state, Illumination has the effect of generating a photocurrent even when no bias is applied to the electrodes; in addition, the junc tion conductance was increased. (C) 1997 by John Wiley & Sons, Ltd.