Structural and spectral studies of MgZnO:Cr 3+ nanophosphors prepared by combustion synthesis

Nanocrystalline MgZn (1− x ) O: x Cr 3+ powders with 0.25 ≤ x ≤ 3.0 mol% were synthesized using the combustion method. Crystallization of MgZn (1− x ) O: x Cr 3+ was investigated using the X-ray diffraction (XRD) technique which point towards significant reduction in crystallite size for MgZnO samples with increasing Cr 3+ concentration. Transmission electron microscopy revealed nanosized grains of the powder. UV–Vis spectroscopy and photoluminescence spectroscopy were employed to establish the electronic and optical properties of nanoparticles. Doping of Cr content from 0.25 to 3 mol% MgZnO facilitated tuning of bandgap in the range 3.37–3.43 eV. In addition to this, PL properties of the samples show that MgZn (1− x ) O: x Cr 3+ possess emission peak at 589 nm. Under excitation at 325 nm, the material exhibits an orange emission with highest relative intensity achieved for 0.25 mol% Cr 3+ . This material may be explored as a new phosphor to be excited by UVA emitting AlGaN LEDs for optical devices and displays.