Organic light-emitting transistors using concentric source/drain electrodes on a molecular adhesion layer

Bottom-contact tetracene light-emitting transistors employing a mercaptosilane derivative self-assembled monolayer as adhesive between gold concentric interdigitated source/drain electrodes and SiO2 gate dielectric are described. Devices that employ the mercaptosilane adhesive have a higher mobility and electroluminescence compared to those employing a standard metallic adhesive. This is rationalized in terms of the large, well interconnected grains found in tetracene films deposited on substrates using the mercaptosilane adhesive. Our work represents a step forward in the understanding of physical processes at semiconductor/metal and semiconductor/dielectric interfaces in organic devices.