Improving the luminescence thermal stability of Ca3Y2Ge3O12:Cr3+ based on cation substitution and its application in NIR LEDs

Abstract

A near-infrared phosphor Ca_3−xSr_xY₂Ge₃O₁₂:Cr³⁺ was synthesized by the solid-state method. When Sr²⁺ replaces Ca²⁺, the thermal stability of the phosphor is obviously improved and the emission intensity at 150 °C can retain 68% of that at room temperature, and its activation energy E_a is 0.331 eV. A novel near-infrared LED was obtained by packaging Ca₃Y₂Ge₃O₁₂:0.01Cr³⁺ and a 455 nm blue chip, and the luminescence intensity increased with increasing working current. The results indicate that this phosphor may have a potential application in near-infrared LEDs.