Single‐Grain High‐Efficiency Full‐Visible‐Spectrum White Emitters

Abstract Full‐visible‐spectrum emission phosphors are promising candidates for next‐generation white light‐emitting diodes (WLEDs), overcoming the complex and high costs of traditional mixed phosphors. However, their practical application is hindered by low luminescence efficiency. In this regard, a generalization strategy is developed that involves creating heterostructure interfaces to prevent detrimental energy transfer processes, thereby boosting efficiency. The SrLiPO 4 /Sr 9 MgLi(PO 4 ) 7 :Eu 2+ single‐grain phosphors prepared in this work have achieved remarkable full‐visible‐spectrum emission efficiency, with record internal and external quantum efficiencies of 76.1% and 56.2%, respectively. The WLEDs encapsulated with this phosphor feature a high color rendering index (≈93.9), a low correlated color temperature (≈3100 K), and stable color performance, indicating that the as‐synthesized single‐grain phosphors are excellent candidates for healthy full‐visible‐spectrum lighting. This innovation is expected to accelerate the development of full‐visible‐spectrum phosphors technology and inspires the creation of more efficient and versatile luminescent materials in the future.