  The modular nature and unique electronic properties of two-dimensional (2D)
covalent organic frameworks (COFs) make them an attractive option for
applications in catalysis, optoelectronics, and spintronics. The fabrications
of such devices often involve interfaces formed between COFs and substrates. In
this work, we employ the first-principles GW approach to accurately determine
the quasiparticle electronic structure of three 2D carbonyl bridged
heterotriangulene-based COFs featuring kagome lattice, with their properties
ranging from a semi-metal to a wide-gap semiconductor. Moreover, we study the
adsorption of these COFs on Au(111) surface and characterize the quasiparticle
electronic structure at the heterogeneous COF/Au(111) interfaces. To reduce the
computational cost, we apply the recently developed dielectric embedding GW
approach and show that our results agree with existing experimental measurement
on the interfacial energy level alignment. Our calculations illustrate how the
many-body dielectric screening at the interface modulates the energies and
shapes of the kagome bands, the effective masses of semiconducting COFs, as
well as the Fermi velocity of the semi-metallic COF.
