Characterizing the Self-Sensing Properties of Photoactive P3H T-Based Nanocomposites

Abstract

In this study, the strain sensing properties of poly(3-hexylthiophene) (P3HT)- based films were characterized using absorption spectroscopy and photocurrent generation. In particular, the objective was to reveal how photocurrent generation and bulk film strain sensitivity were influenced by morphological changes of the bulk heterojunction (BHJ) layer, which consisted of P3HT and fullerene-based [6,6]-phenyl C61 butyric acid methyl ester (PCBM) polymers. Eight different P3HT:PCBM sets were prepared, each with a unique P3HT:PCBM concentration ratio. The absorption spectra of the eight different sample sets were measured, and their sensitivity to strain was characterized. Then, their optoelectronic properties were investigated by measuring their photocurrent generation under light on/off conditions. Lastly, the films’ photocurrent time histories were measured as strain was applied to them. It was found that strain-sensitive photocurrent was observed as a result of strain-induced changes in the light absorption properties of the P3HT:PCBM BHJ layer.