Cr³⁺‐Yb³⁺‐Ni²⁺ Tri‐Doped NIR Phosphors with Spectral Output Covering NIR‐I and NIR‐II Regions

Abstract

To realize efficient and broadband near infrared (NIR) light in both NIR‐I and NIR‐II regions, Gd3Mg0.5Al1.5Ga2.5Ge0.5O12 (GMAGG): Cr3+, Yb3+, Ni2+ phosphors are prepared in this study. The effects of Cr3+‐Yb3+ co‐doping and Cr3+‐Yb3+‐Ni2+ tri‐doping on the luminescence properties are investigated. GMAGG: Cr3+, Yb3+ exhibits high internal quantum efficiency (IQE) of 96.4%, and near‐zero thermal quenching (96.5%@423 K) in 650–1100 nm. By constructing energy transfer from Cr3+ to Ni2+, the emission range of GMAGG: Cr3+, Yb3+, Ni2+ is further extended to 650–1700 nm with a high IQE of 28% and good thermal stability (66%@423 K). The NIR LEDs prepared with GMAGG: 0.04Cr3+, 0.008Yb3+, and GMAGG: 0.04Cr3+, 0.008Yb3+, 0.04Ni2+ exhibit 57.5 and 8.1 mW at an input current of 100 mA, respectively. The results show that GMAGG: Cr3+, Yb3+, Ni2+ is a promising NIR phosphor for NIR light sources.

Blue light-excited broadband NIR-II-emitting Li2ZnSn3O8:Cr3+,Ni2+ phosphor for multifunctional optical applications

“…7,8 In comparison to NIR-I, NIR-II has less background interference, less tissue scattering, deeper tissue penetration depth, and high imaging contrast. 9,10 In addition, dipole moments and bond anharmonicities play a significant role in the typical NIR absorptions that arise from overtones and combinations of fundamental vibrations. However, the behavior of C–H, O–H, N–H, and S–H bonds varies in different substances and corresponds to significant absorptions mainly located in the broad wavelength range above 1000 nm.…”