Influence of overlapping between the fluorescence spectra of dye molecules and the spectrum of plasmon absorption of silver nanoparticles on the luminescence of laser dyes in ethyl alcohol

Abstract

In the present work, the influence of the degree of overlapping between the plasmon absorption spectrum of silver nanoparticles and the luminescence spectra of P6Zh, phenalamine 160, and oxazine 17 on their luminescence was studied. With the addition of Ag NPs to the ethanol solution, the absorption of dyes depends on the concentration of Ag nanoparticles. The overlapping integrals between the plasmon absorption spectrum of Ag NPs and the absorption spectra of the studied dyes were 24.2 for P6J, 52 for phenalemine 160 and 38.5 for oxazine 17, respectively. The optical density in the maximum increased 1.6-fold for P6Zh, 1.4-fold - for phenaleamine 160 and 1.2-fold - for oxazine 17. It was established that for P6Zh the fluorescence intensity reaches its maximum value at a concentration of C = 2 ×10^-6 mol/l, for phenalemine 160 - at C = 5 ×10^-6 mol/l, and for oxazine 17 at C = 10^-5 mol/l. The intensity of fluorescence of P6Zh increased 1.4 times, phenalemine 160 -1.2 times, and for oksazine 17 - 1.1 times. The generation threshold for P6Zh showed, on average, a tenfold decrease, for phenalamine 160 - it was a 1.4-fold decrease, and for oxazine 17 - a 1.2-fold decrease. The luminescence kinetics of solutions in ethanol in the presence of silver NPs decreased by t ≈ 1 ns for P6Zh, t ≈0.4 ns for phenalemine 160 and t ≈0.1 ns for oxazine 17.