Atomic-scale investigations of charge transfer and excitonic states in mol2Dmat heterostructures (B03)

• Subject Area: Experimental Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 555467911

B03 explores the microscopic nature and the effects of disorder on the excitonic insulator state using scanning tunneling microscopy. It uses the interaction with localized charges to study the nature of the phase transition in TiSe2 and Ta2NiSe5. B03 focuses on the band gap opening at the Fermi level and the formation of a charge density wave accompanying the phase transition. The key question is if these phenomena are hallmarks of an excitonic insulator formation. B03 will analyze changes in bandgap and the appearance of in-gap states vs. molecular coverage.

• DFG Programme: Collaborative Research Centres
• Subproject of: SFB 1772: Heterostructures of Molecules and 2D- Materials
• Applicant Institution: Freie Universität Berlin
• Project Head: Professorin Dr. Katharina Franke