6. 3. 2019 Jan Honolka (MFF UK): 2D Fe-chalcogenides on topological insulator surfaces: structural and electronic properties Abstract: FeSe superconductors (SCs) are quasi two-dimensional (2D) in their crystal structure with a layer unit cell thickness of ~3 Å . Their pairing mechanism is believed to be unconventional, i.e. not phonon-mediated leading to a critical temperature of Tc = 8 K in the bulk. In the last years the interest in Fe-chalcogenide SCs intensified after the SC phase transition temperature of FeSe was found enhanced by more than one order of magnitude in the thin-film limit at interfaces to non-conductive oxides. For an overview see [1]. In my talk I will give an overview of our recent progress in growth of 2D FeSe and FeTe [2] islands on topological insulator surfaces, which is based on scanning tunneling spectroscopy techniques. Further, we analyze electronic properties in surface sensitive angle-resolved photoemission spectroscopy (ARPES) e.g. using NanoESCA facilities in Prague. Here doping effects at the high-symmetry Gamma and M-points of the surface Brillouin zone are visible, which are considered to be crucial for the emergence of superconductivity. [1] X. Liu et al., J. Phys.: Cond. Mat. 27, 183201 (2015) [2] F. Arnold, et al., J. Phys.: Condens. Matter 30 065502 (2018)