Figure 9.

Pressure tuned optical properties. a) PL spectra of 1L WSe₂ at ambient pressure. b) The band structure of 1L WSe₂ at 0 GPa (I), around 2.25 GPa (II), and 4 GPa (III), respectively. c) Photon energy of X and X⁻ exciton peaks as a function of pressure in 1L WSe₂. d) Photon energy of X and X⁻ exciton peaks as a function of pressure in 2L WSe₂. e) Schematic illustration of PL emission color for FL‐CN samples under different pressures. f) Normalized PL spectra of FL‐CN samples at the indicated pressures. a–d) Reproduced with permission.^{[ 221 ]} Copyright 2016, Royal Society of Chemistry. e,f) Reproduced with permission.^{[ 220 ]} Copyright 2020, Royal Society of Chemistry.