Green, affordable, and unprecedented photoluminescence investigation on white emission of Y2O3:Clitoria ternatea floral extract complex to replace conventional Dy3+ doping for wLED

Abstract

The spectroscopic characteristics of the common flower Clitoria ternatea are explored for the first time. When excited, the extract shows two emission crests at 436 and 663 nm corresponding to anthocyanin delphinidin and betalains betacyanin, respectively. For practical utility, the extract is made into thin films, giving a broad emission band from 450 to 530 nm. But by this line, the luminescence spectra showed a falloff with time, through a decay rate of 0.2463 cps/h owing to aging. An anti-oxidizing agent (Y₂O₃)–extract complexes with different extract concentrations (1–5 ml) under different heating conditions (100–200 °C) are produced to overcome this scenario. The XRD and Raman spectra depict the fruitful complex formation in cubic structure with space group Ia3. Using UV–visible info, the bandgap is computed to be 2.381 eV. When Y₂O₃ and Clitoria extract are taken in the same measure, decent emission bands around 450–550 nm and 630–690 nm are observed by the FRET mechanism; giving a ninefold increment in PL intensity with CIE coordinates in the vicinity of near-white light. The trials are repeated numerous times to ensure reproducibility and the outcomes are compared with the conventional Y₂O₃:Dy³⁺-doped system, showing prime results by the Y₂O₃:Clitoria complex (1:1, 100 °C). This unprecedented investigation concludes the enhanced photoluminescence from Clitoria extract, which could replace conventional rare earth doping and provide a novel methodology for designing and fabricating lighting devices.