Fig. 11: Photoluminescence as a function of carrier concentration.
From: Photoluminescence as a probe of phosphorene properties
a Measured PL spectra (solid dark gray lines) under various back-gate voltages. PL spectra are fit to Lorentzians. b PL intensity of exciton and trion (left), drain−source current as a function of gate voltages. The emergence of the charged exciton peak correlates with the onset of electrostatic doping. c Peak energy of exciton and trion as a function of gate voltage. The figure was reproduced with permission from ref. 63. d Measured (dots) and fitted (lines) tunable PL spectra of the 20-layer BP device under different displacement fields from 0 to 0.48 V nm−1. e Bandgap/wavelength tuning of the 20-layer BP extracted from PL spectra (dots) and first-principles based model calculations (line). f Bands of the 20-layer BP near the Γ point at the displacement field of 0.48 V nm−1 in comparison with those of the intrinsic 20-layer BP. Only the five highest valence and five lowest conduction bands are plotted for simplicity of the models. The figure was reproduced with permission from ref. 137.
