A Study on the Effect of Cosolvent Addition Pathway on the Optical and Morphological Properties of P3HT: PCBM Composite Films. Issue 1 (24th June 2014) - Nair, Sarita S.
ABSTRACT In this work, we present an exhaustive study on the effect of a cosolvent addition pathway on the optical, structural, and morphological characteristics of poly(3‐hexyl thiophene) (P3HT): [6, 6]‐phenyl C61‐butyric acid methyl ester (PCBM) composite films. Our recommended pathway of cosolvent addition has shown to benefit the composite film by forming more crystallized and ordered P3HT polymer domains on the film surface as revealed by the UV–vis absorption, grazing incidence X‐ray diffraction (GI‐XRD), and atomic force microscopy measurements. GI‐XRD measurements that were carried out at three grazing incidence angles (0.11°, 0.13°, and 0.3°) also substantiate a more prominent upright concentration gradient of the film processed through the modified method. The contact angle measurement reveals accumulation of more P3HT crystallites at the surface of co‐solvent modified films. A highly quenched photoluminescence signal precise phase separation between the blended components of the modified film, promoting exciton dissociation at the donor–acceptor interfaces during photoinduced excitations.