fig4

Figure 4. (A) The emission and excitation spectra of ZnS:Mn(4%) phosphors. The emission spectra are obtained by different excitation wavelengths; (B) The emission and excitation spectra of ZnS:Mn phosphors at different Mn²⁺ doping concentrations (λ_ex = 340 nm, λ_em = 586 nm). The inset is a plot of the ZnS:Mn emission intensities as a function of Mn²⁺ doping concentrations. The intensity is reduced at a factor of 1/3 in measurement.