Low Dose Photoelectron Spectroscopy at BESSY II: Electronic structure of matter in its native state

Highlights: • High-transmission ArTOFs are ideal for photoemission at low irradiation doses. • The wide angular acceptance allows ArPES without sample rotation. • The high time-resolution enables ultrafast time-resolved studies. - Abstract: The implementation of a high-transmission, angular-resolved time-of-flight electron spectrometer with a 1.25 MHz pulse selector at the PM4 soft X-ray dipole beamline of the synchrotron BESSY II creates unique capabilities to inquire electronic structure via photoelectron spectroscopy with a minimum of radiation dose. Solid-state samples can be prepared and characterized with standard UHV techniques and rapidly transferred from various preparation chambers to a 4-axis temperature-controlled measurement stage. A synchronized MHz laser system enables excited-state characterization and dynamical studies starting from the picosecond timescale. This article introduces the principal characteristics of the PM4 beamline and LowDosePES end-station. Recent results from graphene, an organic hole transport material for solar cells and the transition metal dichalcogenide MoS₂ are presented to demonstrate the instrument performances.