Exploring the luminescence of tin‐incorporated nickel‐sensitized lithium gallate short‐wave‐infrared phosphors

Abstract

A series of Ni 2+ -sensitized LiGa 5 O 8 nanocrystals doped with varying amounts of Sn 4+ were synthesized via a high-temperature solid-state method. X-ray diffraction and scanning electron microscopy were employed to investigate the microstructure of the LiGa 5 O 8 host, and optical spectroscopy was used to examine the effects of Sn 4+ addition on the emission spectra and persistent luminescence (PersL) properties, which indicated a homogeneous distribution of the constituent elements in the phosphor. The Sn 4+ incorporation led to an approximately sixfold enhancement of photoluminescence intensity at room temperature and decrease in the energy transition of Ni 2+ ( 3 T 2 ( 3 F)→ 3 A 2 ( 3 F)), which resulted in ∼65 nm bathochromic shift in the photoluminescence emission maxima. However, the addition of Sn 4+ dopant led to a decrease in the quantum yield of luminescence compared to that of the original phosphor. Temperature-dependent thermoluminescence measurements revealed that doping of LiGa 5 O 8 with Sn 4+ interfered with the Ni 2+ trap centers. Moreover, Ni 2+ -sensitized Sn 4+ -doped LiGa 5 O 8 nanocrystals exhibited an afterglow effect that persisted for up to 300 s.