Uniform Surface Characteristics in Sequentially Polymerized Polyurea Films

Abstract

We successfully fabricated uniformly aligned polyurea thin films using molecular layer deposition (MLD) technique. By measuring the film thickness as a functional of the number of cycles, we confirmed the linear growth behavior of the polyurea MLD film. We also fabricated a spin-coated polyurea films after synthesis of the polyurea polymer in solution, and compared their roughness and surface potential with the prepared MLD film. The polyurea MLD film had a low root-mean square value and homogeneous surface potentials, whereas the spin-coated film had very rough surface and a highly variable surface potential. We believe that our results will contribute to performance improvement of polymer-based electrical devices and provide greater insight into the fabrication of uniformly aligned polymer thin films. Table S1. All FTIR peaks measured for the polyurea film along with vibration mode assignment for the in situ FTIR spectra of the (PDI/PDA)n polyurea MLD film. Figure S1. Two-dimensional (a) AFM and (b) SKPM images of the bare Si (100) wafer. (a) The surface of the bare Si (100) wafer is smooth with a RMS roughness of 0.068 nm, in agreement with the line profile. (b) At a 0 V sample bias, the average surface potential is 0.161 V and the standard deviation of the surface potential is 0.024 V. The scan area of each image is 4 μm × 4 μm. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.