  Kagome materials have become solid grounds to study the interplay among
geometry, topology, correlation, and magnetism. Recently, semiconductors
Nb3X8(X = Cl, Br, I) have been predicted to be two-dimensional (2D) magnets and
importantly these materials possess breathing kagome geometry. Electronic
structure study of these promising materials is still lacking. Here, we report
the spectroscopic evidence of at and weakly dispersing bands in
breathing-kagome semiconductor Nb3I8 around 500 meV binding energy, which is
well supported by our first-principles calculations. These bands originate from
the breathing kagome lattice of Niobium atoms and have Nb d character. They are
found to be sensitive to polarization of the incident photon beam. Our study
provides insight into the electronic structure and at band topology in an
exfoliable kagome semiconductor thereby providing an important platform to
understand the interaction of geometry and electron correlations in 2D
material.
