Solution-Processed Graphene–Nanographene van der Waals Heterostructures for Photodetectors with Efficient and Ultralong Charge Separation

• DOI: 10.1021/jacs.1c07615
• Publication Date: 2021-10-07T17:32:59Z
• Authors: Zhaoyang Liu; Haixin Qiu; Shuai Fu; Can Wang; Xuelin Yao; Alex G. Dixon; Stéphane Campidelli; Egon Pavlica; Gvido Bratina; Shen Zhao; Loïc Rondin; Jean-Sébastien La...; Akimitsu Narita; Mischa Bonn; Klaus Müllen; Artur Ciesielski; Hai I. Wang; Paolo Samorì
• Keywords: Exfoliation joint; Charge carrier

Sensitization of graphene with inorganic semiconducting nanostructures has been demonstrated as a powerful strategy to boost its optoelectronic performance. However, the limited tunability optical properties and toxicity metal cations in sensitizers prohibits their widespread applications, in-depth understanding essential interfacial charge-transfer process within such hybrid systems remains elusive. Here, we design develop high-quality nanographene (NG) dispersions large-scale production using high-shear mixing exfoliation. The physisorption these NG molecules onto gives rise formation graphene-NG van der Waals heterostructures (VDWHs), characterized by strong interlayer coupling through π-π interactions. As proof concept, photodetectors fabricated on basis VDWHs show ultrahigh responsivity up 4.5 × 107 A/W specific detectivity reaching 4.6 1013 Jones, being competitive highest values obtained for graphene-based photodetectors. outstanding device characteristics are attributed efficient transfer photogenerated holes from NGs long-lived charge separation at interfaces (beyond 1 ns), elucidated ultrafast terahertz (THz) spectroscopy. These results demonstrate great potential prototypical building blocks high-performance, low-toxicity optoelectronics.