Unique p–n Heterostructured Water‐Borne Nanoparticles Exhibiting Impressive Charge‐Separation Ability

Abstract

The ecofriendly synthesis of organic semiconductors with heterojunctions is of interest and requires surfactants to stabilize colloidal nanoparticles (NPs) in aqueous solution. The use of conventional surfactants results in p-n heterostructured NPs, in which both p- and n-type semiconductors are phase separated and confined within a core surrounded by the surfactant shell. The performances of these devices, however, are not comparable to those of solid organic semiconductor films. Further efforts are required to understand and control the morphological structure of the nanoparticles to improve their performances. Here, by using a new class of polyethyleneglycol-based surfactant, PEG-C60, we synthesized unique p-n heterostructured water-borne NPs that comprise a p-type semiconductor core and an n-type PEG-C60 shell. We demonstrate that the morphology gives rise to charge separation superior to conventional water-borne NPs. These PEG-C60-based water-borne NPs can, thus, provide a new paradigm in the current field of water-based organic semiconductor colloids.

Control of Shell Morphology in p–n Heterostructured Water‐Processable Semiconductor Colloids: Toward Extremely Efficient Charge Separation

“…In the previous work, we used ultrasonication with 32000 Hz when the PC60 was agitated. At that time, we obtained a cluster of PC60 micelles . We hypothesized that individual PC60 micelle is more efficient to control its structure and effective to attach onto the core part of the NPs rather than the cluster formation.…”

“…In a previous work, we introduced a new surfactant, PC60, which is composed of an n‐type semiconducting fullerene molecule ([6,6]‐phenyl‐C61‐butyric acid methyl ester, PC 61 BM) grafted with a polyethylene glycol (PEG) chain . Consequently, precisely phase‐separated heterojunction NPs with a core (p‐type)‐shell (n‐type) morphology were obtained, and they showed superior charge separation properties through efficient electronic interaction between the p‐ and n‐type compounds when compared to the originally reported system.…”

Can Polymer Solar Cells Open the Path to Sustainable and Efficient Photovoltaic Windows Fabrication?

“…In fact, PEG‐C60 has been employed to generate donor‐acceptor blend nanoparticles (NPs) formed in water through the miniemulsion process with the adequate morphology for efficient charge separation . Landfester et al .…”

“…[50] Employing polymers such as PT6S and PT6N associated with water-soluble fullerenes such as the PEGylated C60 might be an efficient method to produce water-soluble active layers for eco-friendly PSC fabrication (PEG-C60, Figure 8(a)). [51] In fact, PEG-C60 has been employed to generate donoracceptor blend nanoparticles (NPs) formed in water through the miniemulsion process with the adequate morphology for efficient charge separation. [51] Landfester et al were actually the first to introduce the miniemulsion process based on nonconducting surfactants, sodium dodecyl sulfate (SDS, Figure 8(a)), for the formation of conjugated polymer-based water-dispersed NPs (Figure 8(b)).…”

“…[51] In fact, PEG-C60 has been employed to generate donoracceptor blend nanoparticles (NPs) formed in water through the miniemulsion process with the adequate morphology for efficient charge separation. [51] Landfester et al were actually the first to introduce the miniemulsion process based on nonconducting surfactants, sodium dodecyl sulfate (SDS, Figure 8(a)), for the formation of conjugated polymer-based water-dispersed NPs (Figure 8(b)). [52] Although most attempts to fabricate PSCs using water-processed NPs (WPNPs) lead to low PCEs (< 1 %), [53,54] a few successful examples of efficient devices can also be found in literature.…”