White-light emission from Y2SiO5:Ce3+, Tb3+ and Sr2Si5N8:Eu2+ phosphor blends: a predictive model

In recent years, there has been an increasing interest in developing multifunctional materials that can be used in different areas, such as artificial lighting. White light-emitting diodes offer the possibility of efficient, safe, and reliable solid-state lighting. This study presents a synthesis and characterisation process of a white-light emitting phosphor based on the combination of rare earth-activated Y2SiO5:Ce3+, Tb3+ (YSO) and Sr2Si5N8:Eu2+ (SSN) phosphors. The YSO phosphor was prepared by combustion synthesis, whereas the SSN phosphor was prepared by solid-state reaction under N2/H2 atmosphere. Photoluminescence measurements showed the contribution of a broad-band emission of Ce3+ ions located in the blue region of the electromagnetic spectrum, a well-defined green emission of Tb3+ ions with the main peak located at λ Em = 545 nm in the YSO phosphor, and a broad-band emission in the red region due to Eu2+ ions in the SSN phosphor. It is worth mentioning that excitation wavelength was in long UV radiation at 360 nm. In addition, a predictive model simulating and modelling the rare earths’ molar percentages to approximate to the D65 white light chromaticity coordinates is presented.