Modification of TiO2 Heterojunctions with Benzoic Acid Derivatives in Hybrid Molecular Solid-State Devices

Control of semiconductor device performance has been investigated by introduction of a series of organic molecule layers at the heterojunction between TiO2 and the p-type semiconductor spiro-MeOTAD (see Figure). The variation of the current–voltage characteristics of these devices, as well as the change in the workfunction of the molecules' modified TiO2 surfaces can be correlated with the molecules' dipole moments.