Multifunctional Near-Infrared Phosphors Cr³⁺/Ni²⁺ Codoped Mg₃Ga₂GeO₈ Based on Energy Transfer from Cr³⁺ to Ni²⁺

Abstract

Currently, near-infrared (NIR) light-emitting materials have been widely used in many fields, such as night vision, bioimaging, and nondestructive analysis. However, it is difficult to achieve multifunction in certain NIR light emitting phosphor. Herein, we propose a new near-infrared phosphor Mg 3 Ga 2 GeO 8 :Cr 3+ ,Ni 2+ that can be applied to at least three fields, i.e., identification of compounds, temperature sensing, anticounterfeiting, and other applications. The multifunctional material exhibited efficient broadband emission of 650−1650 nm under 420 nm excitation. The emission intensity of Ni 2+ in Mg 3 Ga 2 GeO 8 :Cr 3+ ,Ni 2+ is enhanced by two times compared with that of Ni 2+ in Mg 3 Ga 2 GeO 8 :Ni 2+ due to the energy transfer process. Compared with phosphor single doped with Ni 2+ , Mg 3 Ga 2 GeO 8 :Cr 3+ ,Ni 2+ is more convincing in organic compound recognition because it is based on two emission bands: 600−1100 nm and 1100−1650 nm. As a temperature sensor, Mg 3 Ga 2 GeO 8 :Cr 3+ ,Ni 2+ is an ideal temperature-sensing material. This work not only provides a super broadband NIR emitting phosphor with multiple functions but also presents a practical approach for the development of high-efficiency and multifunctional NIR phosphors.