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Novel photodetectors based on graphene, 2D materials, and colloidal Quantum Dots

Graphene has shown unique properties as 2D material, which provides researchers a sheet crystal with remarkable electrical properties. Moreover, owing to its Dirac cone in the band structure, it exhibits a very broad spectral absorption range. However, its quantum yield is comparably week given the low universal absorption of 2.3%. This is where other 2D materials with semiconducting properties and colloidal quantum dots (cQDs) come into play. Their optical properties are superior to the ones of graphene, allowing us to functionalize graphene-based structures for efficient photodetection.

In this project work, we offer you to get involved in the study of electro-optical properties of 2D-material-based structures that are fabricated by simple means in Marburg in order to achieve novel device concepts that effectively convert as many as possible photons to an electrical response. The work will be conducted in collaboration with partners from the Zhejiang University of Hangzhou, China.

Suitable graphene-cQD and graphene-2D-semiconductor combinations are envisioned. For any of these structures, certain device properties need to be analyzed. In addition to the use of light-absorbing nano-thin sheets, quantum dots and nanoparticles can boost the performance of light detection with 2D structures/materials.

What will you learn in our team: You will use common microscopy and spectroscopy techniques in order to characterize 2D materials and graphene photodetectors functionalized by cQDs. Furthermore, you will become acquainted with a simple fabrication method to produce own graphene field-effect transistors and microscale photodetectors. Your first practical experience in the field of optoelectronics and semiconductor spectroscopy will equip you with insight and understanding regarding micro/ nanosciences and structures.

Contact: Dr. Arash Rahimi-Iman

You may find additional information on "Spectroscopy on new materials and nanophotonics" in our research sector.