Morphology and electrical transport in pentacene films on silylated oxide surfaces

摘要

A study comparing the morphology and electrical transport properties of pentacene films on underlayers of different self-assembled monolayers (SAMs) is presented. The SAMs studied as underlayers were phenyltrichlorosilane, n-octadecyltrichlorosilane, and t-butyldiphenylchlorosilane. Pentacene thin films were grown by vacuum sublimation on SiO_2 surfaces treated with self-assembled monolayers. During deposition, substrates were held at a temperature of 70 deg C. The morphologies of the films at different stages of deposition were studied by atomic force microscopy, and the transport properties of the films were characterized by I-V measurements in a simple field-effect transistor (FET) structure. The SAM underlayers strongly influence the film morphology in the first few molecular layers and hence significantly impact the electrical transport in the resulting FETs.