Spectroscopic study of tunable white light stimulation from organic dyes infused in silica

Abstract

The present article reports the stimulation of white emission and spectroscopic investigations of composite material having organic molecules (Coumarin 102 and Rhodamine 6G) infused porous nano-silica matrix coated with a hydrophobic layer and a polymer layer. Electron microscopy reveals the formation of ~ 70 nm particles with a surface area of ~ 112 m²/g and pore volume of ~ 0.440 cm³/g, as the BET surface analyzer estimated. A nano-silica composite containing fluorescent dye molecules in an appropriate ratio produces complementary colours (blue/yellow), allowing the achievement of bright white light emission and the feasibility of white light tuning. The chromaticity coordinates were estimated to be (0.35, 0.33) on excitation with 405 nm LED. The radiative decay time of ~ 4.3ns for C102 was estimated using time-resolved emission spectroscopy, which was found to be a function of Rh6G (~ 4.8ns) concentration. The critical transfer distance and rate of transfer were reported for different concentrations. The thermal stability of the composite against the optical performance in the temperature range of 273 K to 325 K was also reported. We demonstrated synthesized materials as coating materials on the blue LED, which emits blue-dominated white light and latent fingerprinting. The details of photophysics and analysis are explained in the present article.