Peng Cao, Tingxuan Yang, Ting Zhang and Timothy Christopher (University of Auckland) and collaborators (McDiarmid Institute, Te Herenga Waka–Victoria University of Wellington, Jiangsu University of Science and Technology, ANSTO, China University of Mining and Technology)
Energy efficient white light-emitting diodes (WLEDs) have a wide range of applications due to their long lifespan. They provide versatile design options for a variety of applications, such as lighting, backlighting for screens and signage, car headlights and cameras.
Developing WLEDs with high quantum efficiency, high thermal stability and narrow band emission can be challenging. Advanced structural characterisation is essential to design and develop WLED materials with optimised performance.
The team developed a high-performance blue emitting phosphor that exhibits high quantum efficiency and high thermal stability, using a defect engineering approach where the ratio of Sr and Ba was varied until optimised. The high resolution of the Powder Diffraction (PD) beamline was used to establish the effect of cationic substitution on the structures and gain insight into changes to the lattice parameter, phase purity and distribution of Sr and Ba atoms. This work established that the materials formed a solid solution with no unwanted structural changes.
The research resulted in a superior WLED ultra-narrow blue emitting phosphor of KS1.25BP: Eu2 phosphor with enhanced thermal stability. The phosphor's ultra-narrow emission, high quantum efficiencies, and superior thermal stability make it a promising candidate for WLED applications, potentially improving the performance and longevity of the diodes.
Reference:
Yang T, Zhang T, Huang S, Christopher TD, Gu Q, Sui Y, Cao P. 2022. Structure tailoring and defect engineering of LED phosphors with enhanced thermal stability and superior quantum efficiency. Chemical Engineering Journal 435 (1) 133873. https://doi.org/10.1016/j.cej.2021.133873
