A novel high-efficiency near-infrared phosphor Mg0.9Ta2Zn2.1O8:Cr3+,Yb3+ for spectroscopy applications†

Abstract

Near-infrared phosphor-converted light-emitting diodes (pc-LEDs) exhibit significant potential for applications in information encryption, medical diagnostics, and bioimaging owing to their distinct advantages. Nonetheless, advancing near-infrared phosphors with exceptional emission efficiency and enduring thermal stability continues to pose a significant challenge. In this study, a novel near-infrared phosphor, Mg_0.9Ta₂Zn_2.1O₈:Cr³⁺ (MTZO:Cr³⁺), was successfully synthesized. MTZO:Cr³⁺ demonstrates intense broadband near-infrared emission within the 700–1200 nm range, featuring a full width at half maximum (FWHM) of 148 nm, impressive internal quantum efficiency (IQE = 88.1%), and excellent thermal stability. Additionally, we strategically harnessed the energy transfer from the Cr³⁺ ions to Yb³⁺ ions to produce a MTZO:0.006Cr³⁺,0.04Yb³⁺ phosphor, achieving a marked enhancement in thermal stability. Moreover, a near-infrared pc-LED was developed by coupling the MTZO:Cr³⁺,Yb³⁺ phosphor with a commercial blue LED chip. The device exhibits a photoelectric efficiency of 8.11% at a driving current of 100 mA and a peak near-infrared output power of 24.14 mW under identical conditions, highlighting its potential for secure information encryption, night vision, and non-destructive testing applications.