A New Class of Water-Borne Nanoparticles with Unusal p-n Heterostructure for Superior Charge Separation Property

Eco-friendly synthesis of organic semiconductors with heterojunctions has been of interest, which requires surfactants to stabilize the colloidal nanoparticles (NPs) in aqueous solution. Use of conventional surfactants results... [ view full abstract ]

Eco-friendly synthesis of organic semiconductors with heterojunctions has been of interest, which requires surfactants to stabilize the colloidal nanoparticles (NPs) in aqueous solution. Use of conventional surfactants results in the p-n heterostructured NPs, where both p- and n-type semiconductors are phase-separated and confined within a core surrounded by the surfactant shell. Their device performances however have not been comparable to solid organic semiconductor films. Further efforts are required to understand and control the morphological structure of the nanoparticles and thus improve their performances. Here, using a new class of surfactant, PEG-C60, we synthesized a unique p-n heterostructured water-borne NP that comprises of p-type semiconductor as a core and n-type PEG-C60 as a shell. We demonstrate that the morphology allows superior charge separation over conventional water-borne NPs. These PEG-C60-based water-borne NPs, thus, can open up and provide a new paradigm in the current fields of water-based organic semiconductor colloids.