Multi peak emission and morphological evolution of Fe-doped ZnOs nanoflowers

The nanoflowers and nanoblocks of Fe-doped ZnO (i.e. ZnO doped with 0, 1, 2, 3, 4 and 5% Fe) were synthesised by co-precipitation technique. XRD analysis showed that the samples have wurtzite structure containing mostly Fe3+ in the samples with 1% Fe and a mixture of Fe3+ and Fe2+ in the samples with higher amount of dopant. Morphology transformations from nanoflowers to nanoblocks, then into a combination of nanoflowers and nanoblocks were observed. The UV analysis identified the presence of multi-absorption regions in the doped samples. Due to the elevated Fe2+ concentration, the band gap of the 5% doped nanoblocks expanded and behaved irregularly. The room temperature photoluminescence characteristics of the Fe-doped ZnO nanostructures were determined. It was found that, in addition to the detected peaks in the yellow and red regions, the sample doped with 1%Fe shows two peaks in the blue region which could be interesting for multifunctional applications in the field of optoelectronics.