Kory Burns1,Christopher Smyth2,Alex Boehm2,Eric Lang3,Taisuke Ohta2,Jordan Hachtel4,Khalid Hattar5
University of Virginia1,Sandia National Laboratories2,The University of New Mexico3,Oak Ridge National Laboratory4,The University of Tennessee, Knoxville5
Kory Burns1,Christopher Smyth2,Alex Boehm2,Eric Lang3,Taisuke Ohta2,Jordan Hachtel4,Khalid Hattar5
University of Virginia1,Sandia National Laboratories2,The University of New Mexico3,Oak Ridge National Laboratory4,The University of Tennessee, Knoxville5
The resilience of MoS<sub>2</sub> to energetic particles and understanding the chemical modifications induced are of great interest for the realization of long-term space-based electronics incorporating low dimensional materials. In this contribution, we probe these properties in MoS<sub>2</sub> using 10 keV He<sup>+</sup> ion irradiation to alter the chemical composition of MoS<sub>2</sub> enabling selective alterations of the work function. By combining photoemission electron microscopy (PEEM), optical spectroscopy, X-ray photoelectron spectroscopy (XPS), structural characterization, and monte carlo simulations we unveil the role of structural defects in the band onset potential, work function, electron binding energy (E<sub>B</sub>) of the occupied states, and ionization energy. Here, we assess the influence of layer number and substrate interactions in the defect formation process at different fluences. Ultimately, we provide an avenue for efficient testing of the radiation tolerance of low-dimensional materials and analyze the defect-property relationship progression in extreme environments. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.