Effect of a plasma polymerised linalyl acetate dielectric on the optical and morphological properties of an n-type organic semiconductor

Thin films of the n-type, organic semiconductor PDI-8CN 2 were thermally evaporated on two different dielectric surfaces and their optical and morphological properties investigated using Variable Angle Spectroscopic Ellipsometry (VASE) and Atomic Force Microscopy (AFM), respectively. The two dielectric surfaces used were SiO 2 and a plasma polymer derived from the non-synthetic monomer linalyl acetate. The characterisations were performed in order to assess the viability of plasma polymerised linalyl acetate (PLA) thin films as dielectric layers in future Organic Field-Effect Transistor (OFET) devices. These studies resulted in determination of the optical profiles (refractive index and extinction coefficient) in the UV-Vis band of PDI-8CN 2 grown on SiO 2 and an observation of uniaxial anisotropy in the organic semiconductor. This information is useful for the design of opto-electronic devices using PDI-8CN 2 layers. Variations in morphological properties and small variations optical properties were found when the PDI-8CN 2 films were grown on PLA layers, and attributed to the change in surface chemistry between dielectrics.