Effect of high energy ions on the electrical and morphological properties of Poly(3-Hexylthiophene) (P3HT) thin film

The spin-coated thin films of Poly(3-Hexylthiophene) (P3HT) on the glass and Si (double side polished) substrates have been irradiated with 55 MeV Si+4 swift heavy ions (SHI) at fluences in the range from 1 × 1010 to 1 × 1012 ions/cm2. Structural modifications produced by energetic ions are observed by characterization of pristine and irradiated P3HT thin films. Different techniques like high-resolution X-ray diffraction (HR-XRD), micro-Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) were used to analyze the structural changes in the material. A significant increase in crystallinity and room temperature electrical conductivity of P3HT film has been detected on exposure to the heavy ions. The observed increase in the electrical conductivity with increased fluences is explained in the light of improved ordering of polymer chains after irradiation. Mott's variable range hopping model has been used to explain the conduction mechanism in the material in the temperature range of 230–350 K. The modification in surface properties also observed using AFM analysis and contact angle measurement. It is observed that nature of the P3HT thin films remains hydrophobic after irradiation. •P3HT thin films have been irradiated by 55 MeV Si4+ ions.•The increased crystallinity observed.•The improved electrical response due to improved structural properties have studied.•Reordering of polymer chains leads to enhanced conductivity.•Surface properties are also depend on incident ion fluences.