Control of Schottky-diode-barrier height by Langmuir-Blodgett monolayers

The authors show that it is possible to produce near-ideal Schottky diodes of the form GaP/polymeric monolayer/Au, by the Langmuir-Blodgett technique. By modifying poly(styrene/maleic anhydride) in various ways, monolayers with differing headgroup compositions but the same layer thickness were deposited. The resulting devices had barrier heights in the range 1.1¿1.5 eV depending on the headgroups present. A model based on an interfacial dipole layer, due to the headgroups reacting with the oxide layer on the semiconductor, is used to explain these results.