Nanoscale Characterization of the Morphology and Electrostatic Properties of Poly(3-octylthiophene)/Graphite-Nanoparticle Blends

Abstract

Mixtures of poly(3‐octylthiophene) (P3OT) with graphite nanoparticles have been investigated by scanning force microscopy (SFM) techniques. The morphology as well as the mechanical and electrical properties of the blends has been characterized at the nanoscale level as a function of the carbon nanoparticle content in the blend. An increase in the concentration of carbon nanoparticles results in an increase in the surface roughness of the blend and the appearance of distinct regions with well‐defined electrical and mechanical properties. At intermediate concentrations (5–10 wt % of carbon nanoparticles), the samples show pure P3OT regions, as well as round regions containing a mixture of the polymer and carbon nanoparticles, while at higher concentrations (> 15 wt %), the entire sample is composed of this mixture. The interface between the two regions has been studied by electrostatic scanning force microscopy (ESFM) as a function of the applied tip–sample voltage. ESFM provides evidence for the creation of new electronic states at the heterojunction. The observed results can be qualitatively explained in terms of the electronic properties of the individual molecular components, P3OT, functionalized graphite nanoparticles, and their corresponding heterojunction. The implications of these results for organic polymer solar cells are also discussed.

Physical characterizations of semi-conducting conjugated polymer-CNTs nanocomposites

“…In this situation, the exceptional properties of nanoparticles have made them a focus of widespread research in nanocomposite technology [1][2][3].…”

“…Conjugated polymers such as P3OT have been extensively studied [1][2][3][4][5][6][7][8][9][10][11][12][13][14] as promising materials for applications in lightemitting diodes, displays, solar cells or other optoelectronic devices due to their processability, flexibility and low production costs. On the other hand, many important aspects of the electronic and optical properties of these materials are still not fully resolved [6][7][8][9][10][11].…”

Polymer Photovoltaic Cells Based on Solution‐Processable Graphene and P3HT

“…[34][35][36][37][38][39] This is because of a number of factors that limit their technological application, such as impurities in the CNTs, insolubility of the CNTs in common solvents, their polydispersity in length and diameter and the mixture of metallic and semimetallic types of CNT. [45] Besides 0D fullerenes and 1D CNTs, graphene is another allotrope of carbon that is one atom thick with a 2D structure, and has been experimentally demonstrated to be stable at ambient conditions. [46] Pristine graphene has an electron mobility of 10 000 cm 2 V À1 s À1 at room temperature and has a micrometersize two-dimensional plane with a large p-p conjugation.…”

Wavelength dependence of nanoscale photodegradation in poly(3-octylthiophene) thin films

“…Images were acquired working in amplitude modulation mode with typical oscillation amplitudes of 5 nm. Details of the set up and KPM working operation mode are described elsewhere [29]. Platinum coated silicon cantilevers (Budget Sensor k ¼ 3 N/m n 0 ¼ 70 kHz) were used, U ac voltages as low as 500 mV were used at a n elec ¼ 7 kHz.…”