An energy-efficient novel emerald Er3+ doped SrGdAlO4 nanophosphor for PC WLEDs excitable by NUV light

摘要

Novel down-conversion SrGdAlO4:Er3+ nanophosphors with emerald emission were synthesized efficiently with a great success through solution combustion technique. Characterizations regarding crystallographic studies and morphological attributes were practiced by the powder XRD, EDX, SEM and TEM. Refined atomic parameters and positions were calculated for optimal sample SrGd(0)(.)(9)6Er(0)(.)(04)AlO(4) by realizing Refinement technique. The outcomes revealed the tetragonal phase of the doped lattice with 14/mmm (139) space group and particle size of 49.5 nm. EDX confirmed the chemical composition of sample while SEM and TEM images showed the spherical shape of nano particles with their size in the range of 49-55 nm whereas the distance between fringes present in the nanosamples was calculated as 0.204 nm by HRTEM image. FT-IR spectroscopy indicated the presence of stretching vibrations of Al-O bonds in the aluminate type of host lattice by exhibiting sharp peaks at 1154 and 1074 cm(-1). Photoluminescence properties were investigated by recording photoluminescence (PL) excitation and emission, decay curves and diffuse reflectance (DR) spectra. The doped nanophosphor displays the exclusive emerald emission peaks of Er3+ ion subjected to S-4(3/)2 -> I-4(5/2) transition and its optimal concentration was remarked as 4.0 mol%. The value of critical distance (R-c) came out to be 15.91 angstrom which induced both the dipoledipole and electric dipole-quadrupole interrelations as the possible mechanism for concentration quenching. The , detailed description of decay curves depicted the value of life time (0.29 ms) for optimized nanophosphor. DRS specified the band gap (E-g) values for SrGdAlO4 (5.50 eV) as well as SrGd(0)(.)(9)6Er(0)(.)(04)AlO(4) (5.47 eV). CIE coordinates confirmed the emerald emission of novel and energy efficient Er3+ doped nanophosphors which proclaims their potential uses in the PC-WLEDs as well as other opto-electronic devices.