Halide Crystals
In article number 2205981, Ken‐Tsung Wong, Hao‐Wu Lin, and co‐workers demonstrate highly efficient and green emissive manganese halide crystals showing a notable absolute photoluminescence quantum yield ≈ 94% and an unprecedented thermal quenching resistance from 4 to 623 K. The crystals find their applications in phosphor‐converted light emitting diodes, organic light emitting diodes and micro light emitting diodes with a decent external quantum efficiency of 22.7%, a power efficacy up to 102.5 lm W−1 and a luminescence as high as 7,750,000 cd m−2.