Tailoring of hybrid silicon nanocrystal-based bulk heterojunction photovoltaic properties upon nanocrystal laser processing in liquid medium

We report on the role of selected silicon nanocrystal (Si-nc) synthesis techniques on the photoelectric properties of Si-ncs and conjugated poly(hexylthiophene) (P3HT)-based blends. Nanosecond laser processing – both ablation and fragmentation – in liquids and electrochemical etching are employed to fabricate surfactant-free Si-ncs. We demonstrate that the transport properties of the blend can be tuned by the processing conditions. The blends containing Si-ncs produced by laser ablation clearly show superior photovoltaic properties due to the enhanced bulk heterojunction surface area and improved charge transport. Finally, we argue that the nanosecond laser processing in liquid medium could be a flexible and efficient tool to tailor the photoelectric properties of the Si-ncs/P3HT nanocomposites.