Sandwiched confinement of quantum dots in graphene matrix for efficient electron transfer and photocurrent production.

Summary, in English

Quantum dots (QDs) and graphene are both promising materials for the development of new-generation optoelectronic devices. Towards this end, synergic assembly of these two building blocks is a key step but remains a challenge. Here, we show a one-step strategy for organizing QDs in a graphene matrix via interfacial self-assembly, leading to the formation of sandwiched hybrid QD-graphene nanofilms. We have explored structural features, electron transfer kinetics and photocurrent generation capacity of such hybrid nanofilms using a wide variety of advanced techniques. Graphene nanosheets interlink QDs and significantly improve electronic coupling, resulting in fast electron transfer from photoexcited QDs to graphene with a rate constant of 1.3 × 10(9) s(-1). Efficient electron transfer dramatically enhances photocurrent generation in a liquid-junction QD-sensitized solar cell where the hybrid nanofilm acts as a photoanode. We thereby demonstrate a cost-effective method to construct large-area QD-graphene hybrid nanofilms with straightforward scale-up potential for optoelectronic applications.

• Author: Nan Zhu; Kaibo Zheng; Khadga Jung Karki; Mohamed Qenawy; Qiushi Zhu; Stefan Carlson; Dörthe Haase; Karel Zidek; Jens Ulstrup; Sophie Canton; Tönu Pullerits; Qijin Chi
• Department/s: Chemical Physics; MAX IV Laboratory; NanoLund: Centre for Nanoscience
• Publishing year: 2015
• Language: English
• Publication/Series: Scientific Reports
• Volume: 5
• Links: http://dx.doi.org/10.1038/srep09860
• Document type: Journal article
• Publisher: Nature Publishing Group
• Topic: Physical Chemistry (including Surface- and Colloid Chemistry)
• Status: Published
• ISBN/ISSN/Other: ISSN: 2045-2322