- Method achieves high photoresponsivity with a thin active layer
- Enables the creation of ultra-thin optoelectronic devices such as flexible electronics
- Can be used to replace existing composite structures with a single PQD superstructure
Researchers at the University of Central Florida have invented a unique method of creating structures for ultra-thin, highly efficient optoelectronic devices. Current methods (such as depositing PQDs onto a graphene substrate or applying them via spin-coating or dipping) produce structures that offer limited carrier mobility and photoresponsivity. In contrast, the UCF method overcomes these limitations by providing a way to grow PQDs and nanocrystals on any substrate and reduce the separation between them. The resulting structure possesses increased carrier mobility and photoresponsivity.
For example, the inventive group successfully used the method to produce a stable graphene‐perovskite quantum dot (G‐PQD) superstructure with possibly the highest photoresponsivity and thinnest active layer reported. By effectively combining the versatile optical properties of quantum dots (QDs) with the superior electronic and mechanical properties of graphene, the innovation paves the way for a new class of materials for applications in bio-imaging, solar cells, quantum computing and flexible electronics.
The UCF invention provides techniques for growing QDs and nanocrystals on any substrate via a novel defect‐mediated growth mechanism. The method includes placing a precursor on the surface of the material, adding an antisolvent to the precursor, and growing QDs on the surface. Defects can be created by using dry or wet chemistry on one-, two-, or three- dimensional materials such as graphene, carbon nanotubes, or a doped semiconductor. With this method, a structure not only retains the large absorption coefficient and photogeneration efficiency of the QDs, but it also provides the properties of the substrate. The method can be used to replace existing composite structures with a single PQD superstructure. In one example application, the researchers used G-PQD superstructures to make phototransistors. The devices exhibited excellent responsivity of 1.4 × 108 AW–1 and specific detectivity of 4.72 × 1015 Jones at 430 nm.
The research team is looking for partners to develop the technology further for commercialization.
- Enables the development of extremely thin and highly efficient optoelectronic devices
- Offers the ability to develop a new class of high-performing superstructure materials
- Photonic synaptic behavior of PQD-graphene superstructures could provide support for facial recognition and future neuromorphic computing
- High-speed communications
- Phototransistors, photosensors
- High-resolution imaging and displays