Light driven hybrid nanocrystal tmdc capacitors
Sunlight is an intermittent energy source coupled to the availability of the sun. Light-DYNAMO aims for an innovative solution to directly store the solar energy. The challenge is to implement solution-processable light-driven nanocrystal capacitors (NCCs), such as doped metal oxides. They show high charge-storage capacity accumulating multiple delocalized electrons after light absorption. This was to date shown in solution only with the additional drawback of reducing the hole with a sacrificial hole scavenger. The innovative aspect of Light-DYNAMO is to use 2D transition metal dichalcogenides (2D TMDCs), such as MoS2 or WS2, as efficient hole acceptors in a solid state structure. The sensitivity of the TMDCs’ spatial electronic landscape to the local environment (i.e. strain, defects or doping) serves as driving force for energetically driven hole relocation within the TMDC. The electrons instead remain in the NCCs. This results in long-lasting and efficient charge separation and opens novel design principles. In optimized device structures, such stored carriers are extracted. The working principle of the suggested NC/TMDC hybrid device is based on several challenges: first, the absorption and charge storage capacity of the NCCs will be enhanced by exploring novel materials. Second, the TMDC’s sensitivity to the surrounding will be extracted to a high level of control over the 2D energy level distribution. Third, the intentional design of the energy landscape (e.g. through strain manipulation) in the optimized hybrid geometry will be introduced to control carrier redistribution after charge transfer within the TMDC. Finally, appropriate devices for carrier extraction will be structured. The proposal embarks on a pioneering study by the PI on optical control over carrier density in NCC/TMDC hybrids, advancing such novel systems to a level in which the incoming sunlight is harnessed, converted, stored as charges and released on demand to power an electric circuit.