Development of rare-earth-free phosphors for eco-energy lighting based LEDs

Abstract

Several phosphors without rare-earth elements were synthesized by a simple and practical method. Depending on their wavelength emitting range upon UV excitation, i.e. blue, green or red, they were classified in three groups. The phosphors exhibiting the best performances in optical properties were selected to be incorporated in free-standing silicon films and combined with a 365 nm LED. The thermal quenching of phosphors as well as the photometric parameters of the luminescent composite films were investigated. This white emission of the combination between the rare-earth-free phosphors based silicon film and LED shows a CRI >75 and CCT around 4000 K which can fulfil the requirements for indoor domestic lighting source.