Fig. 2

Phase transition of FeS nanosheets. a Structural transition from distorted P\(\bar 6\)2c phase to high-symmetry P63/mmc phase. The displacement vectors are marked by blue arrows. b The band structure of P\(\bar 6\)2c phase. c The band structure of high-symmetry P63/mmc phase. d In situ Raman spectra as functions of temperature with or without NIR light irradiation. e The potential barrier of phase transition as a function of carrier concentration ratio