Near-infrared persistent luminescence in Mn4+ doped perovskite type solid solutions

Abstract

Persistent luminescent phosphors with near-infrared emission have attracted attention in recent years for their promising bio-imaging applications. In the development of persistent materials in the near-infrared wavelengths, Mn4+ is regarded as a promising candidate owing to the 2Eg → 4A2g emission in the deep-red or near-infrared range. In this work, a series of Mn4+ doped perovskite type LaAl1-xGaxO3 and La1-xGdxAlO3 solid solutions with different compositions were successfully prepared using a high temperature solid state reaction method. Mn4+ occupied octahedral positions to substitute Al3+ or Ga3+ in these solid solutions and the 2Eg → 4A2g emission of Mn4+ was tailored by the different local environments of the hosts. Tunable NIR persistent luminescence was achieved by the crystal field control and composition modification. The trap levels of these solid solutions were investigated using thermoluminescence measurements. This kind of perovskite type-based solid solution with tunable near-infrared emission is highly desirable for medical imaging applications.