Fig. 2: Ultrastrong PL emission in 1D vdW FRP.
From: Giant anisotropic photonics in the 1D van der Waals semiconductor fibrous red phosphorus
a Upper panel: the typical AFM image of an exfoliated 1D vdW FRP flake, exhibiting several different thicknesses. Lower panel: height profiles taken along the dotted black line in the upper panel. b Nonpolarized PL spectra (black) for the exfoliated 1D vdW FRP flake in a, excited by a 532 nm (2.33-eV) excitation laser at room temperature. The PL spectra of 1D vdW FRP flake are fit to a sum of Lorentzians, from which we can obtain eight sharp PL peaks, marked as P1–P8. The inset is the energies for the eight PL peaks. Orange line is the PL spectra of monolayer MoS2 measured at the same condition. Traces are vertically offset for clarity. c Time-resolved PL spectra measured with a streak camera. d The time evolution of normalized integral intensity from 600 nm to 700 nm. Red line is a single-exponential fit. The inset is the time evolution of normalized emission intensity at different wavelengths. e Theoretically calculated band structure of 1D vdW FRP. The inset shows the BZ path of primitive cells. f The mapping of Fermi surface for 1D vdW FRP. Red and cyan isosurfaces represent the highest valence band, and blue and yellow isosurfaces denote the lowest conduction band. The expansion of energy is 40 meV.
