Effect of temperature on fluorescence quenching and emission characteristics of laser dyes

Abstract

Effect of temperature on fluorescence quenching and emission characteristics of laser dyes (LD - 473) and (LD - 423) have been investigated in the temperature range 25°C - 65°C by steady state and transient methods. The fluorescence intensity of both dyes is quenched in the presence of quencher aniline at different temperatures. Stern-Volmer (S-V) plots are non-linear showing positive deviation. It has been found that dynamic quenching constant increases with temperature, whereas static quenching constant is independent of temperature. In both the dyes, Fluorescence emission intensity has decreased with increase in temperature and fluorescence band maxima is slightly shifted towards shorter wavelength. Further, fluorescence lifetime has decreased with increase in temperature for both the dyes. The possible deactivation mechanisms are discussed.