A process for preparing a device and a device including a substrate; an interlayer disposed on the substrate, wherein the interlayer comprises a cured film formed from an interlayer composition, wherein the interlayer composition comprises: an epoxy compound; a polyvinyl phenol; a melamine resin; a solvent; an optional surfactant; and an optional catalyst; a source electrode and a drain electrode disposed on a surface of the interlayer; a semiconductor layer disposed on the interlayer, wherein the semiconductor layer is disposed into a gap between the source and drain electrode; a back channel interface comprising an interface between the semiconductor layer and the interlayer, wherein the interlayer serves as a back channel dielectric layer for the device; a dielectric layer disposed on the semiconductor layer; a gate electrode disposed on the dielectric layer. Also an interlayer composition and an organic thin film transistor comprising the interlayer composition.