Using Finnish minerals to produce highly luminescent sodalites for lighting

Soda-lights is a project funded by the Finnish Natural Resources Research Foundation (Suomen Luonnonvarain Tutkimussäätiö) from January 1, 2023 until the end of 2025. The project is led by professor Mika Lastusaari and it employs one researcher.

The most commonly used material in common white LEDs is a yellow-emitting Y₃Al₅O₁₂ doped with cerium (YAG:Ce), which combines with the blue emission from a semiconductor to create white light. The problem with this material is that it contains cerium and yttrium, which are rare earth elements with limited availability, and that is why non-endangered, sustainable elements are needed to be sought after in this field.

The goal of the project is to synthesize sodalite (Na₈Al₆Si₆O₂₄Cl₂), a mineral with unique optical properties, using various Finnish mineral sources including feldspars and spodumene. According to earlier research, sodalite’s visible light emission is dominant in the orange region, but the aim of this work is to shift the wavelength to yellow in order to obtain white light and eventually replace YAG:Ce as the material in LEDs. The utilization of Finnish mineral resources will not only contribute to the development of sustainable materials but also improve the availability of sodalite for various industrial applications in the country and worldwide. The main challenges of the project lie in the unpredictable purity of the natural materials, however in many cases impurities are the key to obtain certain optical properties.