Phase transition and Nd3+/Pr3+ co-doping induced enhancement of NIR emission in ScP3O9: Cr3+ phosphor

Near-infrared (NIR) phosphors play an important role in NIR pc-LEDs. However, NIR phosphor with long wavelength are still suffered from low efficiency and poor thermal stability. Herein, a blue light excitable ScP3O9: Cr3+ NIR phosphor with an emission peak > 880 nm is reported. Significantly, the PL intensity of ScP3O9: Cr3+ increased to 241% when the monoclinic phase changes to cubic. Moreover, by co-doping the cubic ScP3O9: Cr3+ with Nd3+, Pr3+ ions, the PL internal quantum efficiency (IQE) of the phosphors increased from 62% to 74%, and the thermal quenching of the phosphor is suppressed effectively (86% at 423 K). The energy transfer processes between Cr3+ and Nd3+, Pr3+ ions are proposed to be responsible for the enhancement. Furthermore, an efficient NIR pc-LED was fabricated, and gives a high photoelectric efficiency of 16.5% (26.8 mW at 60 mA). Finally, multifunctional applications of the NIR device in night-vision and nondestructive analysis were demonstrated.