Hybrid Inorganic/Organic Nano-Systems for the Development of Light-Driven Storage Devices

The efficient harvesting of solar radiation and subsequent steady-state storage of photo-charges are now becoming one of the main challenges for the development of sustainable energy sources. The growing demand to reduce the usage of rare ^[1] and toxic materials, as well as the need to overcome current limitations in solar energy storage (such as the intermitting nature of the source and inevitable conversion losses) calls for completely innovative approaches. A promising new approach relies on combining light absorption, charge separation, and storage into one single set of solution-processable, environmentally friendly, and Earth-abundant materials as well as the possibility to exploit light-driven multi-electron and hole transfer reactions to improve the charge-storage capability. In this direction, hybrid inorganic/organic nano-systems employing metal oxides nanocrystals (MO NCs) and graphene quantum dots (GQDs) are emerging as potential candidates to fulfill these purposes. In this work, by means of spectro-chemical tools, we investigate the ability of MO NCs (Sn doped In₂O₃ NCs) to quasi-permanently accumulate electrons upon UV light illumination ^[2] as well as their efficient extraction ^[3]. Moreover, by using a widely employed electron-acceptor molecule, namely F4TCNQ, we show the potential of specifically functionalized GQDs to store one hole in their ground state. These evidences point toward the possibility to exploit hybrid inorganic/organic nano-systems as novel multi-charge accumulation components for the development of solution-based light-driven storage devices.<br/>References:<br/>^[1]Gatti et al. “Opportunities from Doping of Non-Critical Metal Oxides in Last Generation Light-Conversion Devices,” Advanced Energy Materials, 2021, 11, 2101041<br/>^[2] Ghini et al. “Photodoping of metal oxide nanocrystals for multi-charge accumulation and light-driven energy storage,” Nanoscale, 2021,13, 8773-8783.<br/>^[3] Ghini et al. “Multi-charge transfer from photodoped ITO nanocrystals,” Nanoscale Advances, 2021, <b>3</b>, 6628–6634