Electronic structure of LaO1-x Fx BiSe2 (x=0.18) revealed by photoelectron spectromicroscopy

We report an electronic structure study on LaO1-xFxBiSe2 (x=0.18) by means of photoelectron spectromicroscopy. The Fermi surfaces and band dispersions are basically consistent with the band-structure calculations on BiS2-based materials, indicating that the electron correlation effects may be irrelevant to describe physics of the new BiSe2 system. In LaO1-xFxBiSe2 (x=0.18), the area of the Fermi pockets is estimated to be 0.16±0.02 per Bi, consistent with the amount of F substitution. Although the spectromicroscopy technique avoids the effect of microscale inhomogeneity for angle-resolved photoemission spectroscopy (ARPES), the ARPES spectral features are rather broad in the momentum space, indicating the likely effect of local disorder in the BiSe2 layer.