In-situ Transmission Electron Microscopy Investigation of WS2 Growth Mechanisms and Density Functional Theory Calculations on WS2

Abstract

Growth processes of WS2 have been studied via in-situ Transmission Electrons Microscopy (TEM) heating experiments. DFT calculations were performed on WS2 to investigate how magnetic properties affect the band-gap. TEM heating experiments taught us, that lattices grow in the temperature range of 100-800 ◦C and faceting occurred at 450 ◦C. With EDX spectroscopy a ratio of 1:2 for W:S has been found, confirming that WS2 is, indeed, formed. DFT calculations indicated that the WS2 structure is not magnetic. However, when magnetic properties are enforced, the band-gap and the fermi-energy is altered. External electric fields can thus be used for band-gap tuning, making WS2 a viable semi-conductor