Structural confinement-induced highly efficient deep-red emission and negative thermal quenching performance in Mn 4+ -activated Ca 7 Mg 2 Ga 6− y Al y O 18 :Mn 4+ phosphors

Extraordinarily high quantum efficiency and abnormal negative thermal quenching were simultaneously achieved in oxide phosphors Ca 7 Mg 2 Ga 6− y Al y O 18 :Mn 4+ by structurally confining Mn 4+ -emitters at isolated octahedral sites.