White light generation and modulation using stacked multilayer nanofibres

Abstract

In this article, the production of white light from single-leaf extract of the Buxus sempervirens shrub is discussed, followed by its modulation using a lanthanide complex i.e. Eu(DBM)₃phen (EDP) dispersed in PVA polymer nanofibres. Luminescent Buxus-semperviren's leaf extract and EDP in PVA nanofibres have been fabricated using the electrospinning technique. The morphological and luminescent properties of fabricated nanofibres were characterized using different techniques. SEM analysis reveals the formation of smooth surfaced and interlinked nanofibres with diameters 136 nm ± 19 nm and 194 ± 29.8 nm for EDP and leaf extract in PVA nanofibres, respectively. Through the UV-visible absorption analysis it was observed that the major absorption of the leaf extract and the EDP in nanofibres lies in the UV-blue regions. The emission spectra presented the red characteristic emission due to ⁵D₀ → ⁷F_J(0,1,2,3,4) transitions of Eu³⁺ ions in EDP. The emission spectra of the leaf extract in PVA nanofibres exhibit three emission bands in the red, green and blue regions, giving a white perception. The red colour emission is ascribed to chlorophyll, and the green-blue emission is due to the cinnamic acids on the epidermis layer of the leaf. White light modulation explored by multilayer stacking of EDP nanofibre's layers. The colour parameters like CIE, CCT and Duv were calculated for different configurations.