High crystallinity parameter poly(3-hexylthiophene-2,5-diyl) thin film fabricated by the electrospray deposition method

Control of the crystallinity parameter and phase segregation of poly(3-hexylthiophene-2,5-diyl) (P3HT) and the soluble fullerene derivative [6,6]-phenyl C61-butyric acid methyl ester (PCBM) is a critical issue for polymer/fullerene-type organic photovoltaic cell applications. In this paper, P3HT thin films and P3HT:PCBM blend thin films were fabricated using the electrospray deposition method. The Raman spectral features of the samples were estimated using a two-peak fitting with a mixture of Gaussian and Lorentzian functions to determine their crystallinity parameters. Then, the relationship between the film morphology and crystallinity parameter was investigated. Homogenous P3HT thin films with high crystallinity parameters were obtained under dry/wet conditions, and a similar trend was found for P3HT:PCBM blend films.