Near-infrared luminescence and temperature sensing properties of Sc2Mo3O12:Nd3+/Yb3+/Ho3+ phosphor

Abstract

Here, a series of Sc₂Mo₃O₁₂:Nd³⁺/Yb³⁺/Ho³⁺ phosphor are synthesized by high temperature solid-state method. The luminescence properties are investigated under 980/808 nm excitation. The strong near infrared(NIR) emission bands of Sc₂Mo₃O₁₂:Nd³⁺/Yb³⁺/Ho³⁺ phosphor are obtained from 700 to 2250 nm. The typical NIR radiation bands of Nd³⁺, Yb³⁺ and Ho³⁺ ions including ∼1060, ∼1000 and 1850–2150 nm are obtained. Moreover, the temperature properties of these NIR emission bands are investigated. The significant thermal enhancement phenomenon of all emission bands are obtained from 303 to 563 K. Under excitation at 980 nm, the emission intensity of Nd³⁺ at ∼808 nm is enhanced by 613-fold from 303 to 563 K for Sc₂Mo₃O₁₂:Nd³⁺/Yb³⁺/Ho³⁺ phosphor. The multiphoton assistance energy transfer(ET) process and negative thermal expansion(NTE) of Sc₂Mo₃O₁₂ host contribute to increase emission intensity. Then, the temperature sensing performances of Sc₂Mo₃O₁₂:Nd³⁺/Yb³⁺/Ho³⁺ phosphor are investigated according to luminescence intensity ratio(LIR) technology. The maximum relative sensitivity(S_R) based on ⁵I₇ → ⁵I₈(Ho³⁺)/⁴F_3/2 → ⁴I_9/2(Nd³⁺) has reached 2.251 % at 373 K. The results indicate that the Sc₂Mo₃O₁₂:Nd³⁺/Yb³⁺/Ho³⁺ sample show thermal enhancement characteristics in NIR emission range, which can be used to design optical temperature sensor.