Co-precipitation Synthesis and Optical Properties of Mn4+-doped Hexafluoroaluminate w-LED Phosphors.

ABSTRACT: Mn4+-activated hexafluoroaluminates are promising red-emitting phosphors for white light emitting diodes (w-LEDs). Here, we report the synthesis of Na₃AlF₆:Mn4+, K₃AlF₆:Mn4+ and K₂NaAlF₆:Mn4+ phosphors through a simple two-step co-precipitation method. Highly monodisperse large (~20 μm) smoothed-octahedron shaped crystallites are obtained for K₂NaAlF₆:Mn4+. The large size, regular shape and small size distribution are favorable for application in w-LEDs. All Mn4+-doped hexafluoroaluminates show bright red Mn4+ luminescence under blue light excitation. We compare the optical properties of Na₃AlF₆:Mn4+, K₃AlF₆:Mn4+ and K₂NaAlF₆:Mn4+ at room temperature and 4 K. The luminescence measurements reveal that multiple Mn4+ sites exist in M₃AlF₆:Mn4+ (M = Na, K), which is explained by the charge com

SUBMITTER: Senden T 

PROVIDER: S-EPMC5706269 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature