Luminescence properties of Ca0.65La0.35F2.35:Yb3+, Er3+ with enhanced red emission via upconversion

Abstract

Under 980 nm excitation, Ca 0.65 La 0.35 F 2.35 :20 mol.%Yb 3+ , x Er 3+ showed intense red upconversion luminescence, which was ascribed to 4 F 9/2 → 4 I 15/2 transition of Er 3+ . The ground-state absorption (GSA), excited-state absorption (ESA) and energy transfer (ET) processes between Er 3+ /Yb 3+ ions and Er 3+ /Er 3 ions were involved in the enhanced red emission mechanism. . ▶ Yb 3+ /Er 3+ codoped Ca 0.65 La 0.35 F 2.35 materials with intense red emission via upconversion were prepared by a high temperature solid-state method. ▶ Ca 0.65 La 0.35 F 2.35 :20 mol.%Yb 3+ , x Er 3+ showed intense red upconversion luminescence, which was ascribed to 4 F 9/2 → 4 I 15/2 transition of Er 3+ . ▶ The green and red emissions are two-photon processes, while both energy transfers between Yb 3+ /Er 3+ and Er 3+ /Er 3+ are involved in the red emission mechanism of the Ca 0.65 La 0.35 F 2.35 :20 mol.%Yb 3+ , x Er 3+ materials. Yb 3+ /Er 3+ codoped Ca 0.65 La 0.35 F 2.35 materials with intense red emission via upconversion were prepared by a high temperature solid-state method. Based on the upconversion luminescence properties investigations, it was found that, under 980 nm excitation, Ca 0.65 La 0.35 F 2.35 :20 mol.%Yb 3+ , x Er 3+ showed intense red upconversion luminescence, which was ascribed to 4 F 9/2 → 4 I 15/2 transition of Er 3+ , although both green and red emissions could be detected. It was also found that the green and red emissions originated the two photon processes, and the ground-state absorption (GSA), excited-state absorption (ESA) and energy transfer (ET) processes between Er 3+ /Yb 3+ ions and Er 3+ /Er 3 ions were involved in the enhanced red emission mechanism.