Characterization and Distribution of Poly(3‐hexylthiophene) Phases in an Annealed Blend Film

The characteristic absorption spectra of three kinds of phases, the isolated, ordered, and disordered phases, in a solvent-vapor annealed poly(3-hexylthiophene)/[6,6]-phenyl-C61 -butyric acid methyl ester (P3HT/PCBM) blend film were studied by means of spectroelectrochemistry (SEC) and time-resolved absorption spectroscopy (TAS). The results reveal that the content of three phases are 12 % isolated, 37 % ordered, and 51 % disordered for the annealed P3HT neat film, and 25 % isolated, 31 % ordered, and 44 % disordered for the annealed P3HT/PCBM blend film. The vertical distribution of the different phases in the blend film was studied by SEC, and the results show that the ordered and isolated phases are mainly distributed in the top and in the bottom of the annealed films, respectively, while the disordered phase is mainly distributed in the middle and the bottom of the films.