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Photoluminescence characteristics of Ln3+-doped phosphors derived from sustainable resources for solid state lightning applications
Author(s)
Reddappa, R.
Devi, L. Lakshmi
Basavapoornima, Ch
Depuru, Shobha Rani
Kaewkhao, J.
Jayasankar, C. K.
Date Issued
August 1, 2022
Type
Article
Abstract
Di-calcium silicate (Ca2SiO4) phosphors doped with series of Ln3+ ions have been prepared by using high temperature solid-state reaction technique. The required raw chemicals of CaO from egg shell and SiO2 from rice husk powders have been used instead of chemicals which were derived from non-renewable minerals. The structural, morphological and photoluminescence characteristics were studied through XRD, SEM and FLS 980 spectrometer measurements, respectively. The XRD patterns of all the phosphors are fit well with the established ICDD card No.01–083–0464 with monoclinic crystal structure. Photoluminescence spectra of Ce3+, Pr3+, Sm3+, Eu3+, Tb3+, Dy3+ and Er3+-doped phosphors exhibit characteristic sharp intense emission peaks at 385 (d-f), 606 (1D2→3H4), 600 (4G5/2→6H7/2), 703 (5D0→7F4), 544 (5D4→7F5), 573 (4F9/2→6H13/2) and 545 nm (4S3/2→4I15/2), respectively. Emission characteristics of developed phosphors such as CIE co-ordinates, correlated colour temperature, colour purity, lifetimes of fluorescent level, etc., of Ln3+ have been quantified. The decay curves for lower concentrations of Ln3+ ion exhibit single exponential behaviour and turns into bi-exponential behaviour accompanied with shortening in lifetime for higher concentrations. These results have been discussed with reported values and found to be better than many of the reported phosphors derived from non-renewable minerals. Therefore, Ca2SiO4:Ln3+ phosphors could also be useful to design and develop low-cost solid state lightning devices besides effective utilization of renewable agricultural and food waste materials.
Citation
Optik, 264, 2022