Investigation of novel hybrid / charge transfer excited states at 2D/0D heterointerface

• Applicant: Dr. Mahfujur Rahaman, Ph.D.
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2021 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 461242706

The major goal of this project is to gain fundamental understanding of charge transport, transfer and photon emission mechanisms at atomic and molecular scale 0D/2D interfaces via assembly and engineering of new structures and interfaces, hitherto unexplored in quantum materials. Structural-property relationships dictating quantization and localization of tightly bound excited states (both intralayer and interlayer or charge transfer excitons) based on the symmetry and interfacial chemistry will be established using confluence of synthesis and characterization techniques: metal organic chemical vapor deposition (MOCVD), scanning near-field optical microscopy (SNOM), TERS/TEPL as well as far field PL and absorption spectroscopy. The material class under consideration for this purpose are 2D semiconductors of structure MX2 (M = Mo, W, Re; X = S, Se) and 0D semiconductors of core/shell type Cd and Zn based chalcogenides. The key objectives are to develop a controlled 2D/0D mixed dimensional heterostructure using growth, nanofabrication and colloidal self-assembly techniques, to measure the absorption and PL properties in both far and near field to determine the nature of excitons and charge transfer, to measure charge transport and photocurrent to understand the nature of band bending and alignment at the interface using scanning probe techniques, and to exploit the system to understand the effect of interface atomic and electronic structure as well as light-matter-interaction in a plasmonic field on the luminescence property.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professor Dr. Deep Jariwala