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MOPTOPus Project

The physical and electrical connection of nanoscale functional materials to devices with dimensions several orders of magnitude larger impacts the nanomaterials’ structural and thus optoelectronic properties. A contactless approach to their optoelectronic manipulation at length scales relevant to critical properties will open a manifold of new possibilities for their investigation and application. Within MOPOTPus, we aim to implement a novel, contactless nano-manipulator of several nanometers controlled purely by light. To achieve this, degenerately doped metal oxide nanoparticles will be utilized, whose carrier densities in the range of 1021 cm-3 can be largely tuned upon photo-doping and capacitive charging. The controlled manipulation of their carrier density by exciting with light in the region of the interband transition in the ultraviolet/visible (UV/vis) range will deliver an optically driven nano-gate, where the nanometer scale local potential is controlled only by the light intensity and energy. A deliberate charge release of the previously introduced charge carriers will then lead to local electron transfer, prompted upon plasmon induced ‘hot’ electron extraction with low-energy light pulses in the region of the localized surface plasmon resonance (LSPR) in the near infrared (NIR). This will result in a light driven nano-device converting local light energy to electrical energy based entirely on optical triggers. In particular, these optically-driven nano-devices represent near-optimal dynamic manipulators of local (opto)electronic properties in layered two dimensional transition metal dichalcogenides (2D-TMDCs) and other layered 2D materials, which are extremely susceptible to local electrostatic field and potential changes. Simple drop casting of the metal oxide nanoparticles on top of the nanostructure and manipulation with UV/vis and NIR lasers will enable the nanoscale manipulation of the local potential and/or localized charge transfer. The establishment and fundamental understanding of the nano-device, combined with high resolution near-field microscopies will allow us to map critical optical properties of the layered 2D materials–nano-device systems at their native length scales.