Cool green light emitting GdAlO3:Tb3+ perovskite nanomaterials: Crystal structure and spectroscopic characteristics for advance display appliances

Abstract

Using the gel-combustion process, pure-phase GdAlO3 (GAP) perovskite phosphor doped with different concentration of Tb3+ ion has been synthesized. XRD, TEM, FTIR, PL/PLE and fluorescence decay studies were used to characterize the materials in detail. On the basis of powder XRD data, phase evolution of perovskite material with respect to the various content of trivalent terbium ion has been examined, and the rietveld technique has been used to further refine the structural characteristics of the orthorhombic phase. Among all the samples, nanosample (x = 0.05, known as optimized sample) was found with high crystallinity and intensity and further their calcination effect was also investigated. TEM investigation revealed the formation of nanoparticles with some agglomeration. When excited at 272 nm, a series of characteristic emissions bands of Tb3+ doped GdAlO3 phosphors were detected in the emission spectra at about 492 nm, 542 nm, 589 nm, and 624 nm, which resemble to the 5D4→7F6, 5D4→7F5, 5D4→7F4, and 5D4→7F3 transitions, individually. The most intense band detected at 542 nm (5D4→7F5) is responsible for the green color in the synthesized material. The lifetime of Tb3+ emission was determined to be gradually declining with concentration of Tb3+ ions using fluorescence decay analysis. The derived values of CIE chromaticity coordinates (x, y) were quite closer to the NTSC standard value of green emission which further validates their applicability in display application and other lighting foundations.