Tailoring the photoluminescent properties of samarium and dysprosium codoped calcium zirconate perovskites for WLED applications

Abstract

This study investigates the photoluminescent properties of Dy3+/Sm3+ single and codoped CaZrO3perovskites that were prepared through conventional solid state ceramic route method. X‐ray diffraction studies confirmed the orthorhombic (Pnma) perovskite structure of the calcined samples. Photoluminescence studies of Dy3+doped CaZrO3 systems showed emission peaks at 484 nm and 575 nm due to the transition between 4F9/2–6H15/2 and 4F9/2–6H13/2 levels respectively. Intense red emissions were observed for Sm3+ doped CaZrO3 systems at around 567 nm, 603 and 646 nm that corresponds to the 4G5/2 → 6H5/2, 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 transitions of Sm3+. Two different emissions were observed at different excitations for Dy3+/Sm3+ codoped CaZrO3systems. Pleasant white light emission was achieved for the CaZr0.9Sm0.025Dy0.075O3 system at 354 nm excitation with CIE color coordinates (0.3310, 0.3349) with a quantum yield of 16.14%, makes this system a promising candidate for WLED and display device applications. Uniform grain morphology and elemental composition of CaZr0.9Sm0.025Dy0.075O3 sample was revealed from scanning electron microscopic and electron dispersive X‐ray analysis. The presence of elements and their oxidation states in the calcined samples for doubly doped system was confirmed from X‐Ray photoelectron spectroscopicstudies.

Fabrication and characterizations of Cr3+‐doped ZnGa2O4 transparent ceramics with persistent luminescence

“…), main group elements (Bi 3+ , etc. ), and some crystal defects show their characteristic phosphorescence 2–7 . Since Matsuzawa et al discovered the continuous luminescence of SrAl 2 O 4 :Eu 2+ , Dy 3+ more than 20 years ago, this material has attracted extensive attention.…”