As shown in Figure , PLVP-3 solution with low concentration (0.1 mg/mL) can only a Abbreviation: λab = absorption wavelength, λex = excitation wavelength, λem = emission wavelength be excited in a narrow range, i.e., 330-360 nm. However, the concentrated solution of PLVP-3 exhibited obvious excitation-dependence on emission. For example, the emission of 5 mg/mL PLVP-3 solution red-shifted from 410 nm to 480 nm when the excitation wavelength was changed from 330 nm to 400 nm. As the concentration reached 50 mg/mL, the emission at 410 nm disappeared and the strongest emission at 480 nm can be obtained with the excitation wavelength of 390 nm (Figure ). Also, as the concentration of PLVP-3 increases, the UV absorption band edge red-shifted (Figure ). Similar results are observed in the other PLVPs (Figure ). These results suggest that new luminophores with smaller bandgaps could generate in PLVP solutions with increased concentration.