Synthesis and optoelectronics properties of diblock copolymer of P3HT containing thiol-side chains and its hybrid nanocomposite

Abstract

Although the solid-state microstructure of semiconducting polymers is well known to influence properties in optoelectronic devices, the control of desired aggregation in solution and film remains relatively rare. Here, diblock copolymer poly(3-hexylthiophene)-b-poly(3-thiophenehexanethiol) (DP-P3HT-SH) has been synthesized by a simple synthetic technique, and different aggregation states of DP-P3HT-SH and its respective hybrid nanostructures DP-P3HT-S-AuNPs had been prepared to research the influence of aggregate morphology on photoelectric performance. The diblock copolymer DP-P3HT-SH could be prepared with different aggregation states, i.e., global (G), leaf-like (L) and elliptical (E) shape states. The DP-P3HT-S-AuNPs composites exhibited a wider absorption band than the DP-P3HT-SH polymer and showed photoluminescence (PL) quenching. The amount of PL quenching of the three aggregation states was 23%, 11% and 21%, respectively, which illustrated that the charge transfer between GDP-P3HT-SH and AuNPs was the most efficient among these three aggregation states. In addition, the conductivity of these three aggregation states of DP-P3HT-SH could be improved by the addition of AuNPs and the increase of film thickness. Therefore, the semiconducting polymer–metal composites could be used to design new optoelectronics materials by tuning the aggregation state of the diblock copolymer to modulate device characteristics.