Enhanced photoluminescence properties of electrospun Dy -doped ZnO nanofibres for white lighting devices.

Dy -doped ZnO nanofibres with diameters from 200 to 500 nm were made using an electrospinning technique. The as-fabricated amorphous nanofibres resulted in good crystalline continuous nanofibres through calcination. Dy -doped ZnO nanofibres were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), ultraviolet-visible (UV-vis) light spectroscopy, Fourier transform infrared spectroscopy (FTIR), and photoluminescence (PL). XRD showed the well defined peaks of ZnO. UV-vis spectra showed a good absorption band at 360 nm. FTIR spectra showed a Zn-O stretching vibration confirming the presence of ZnO. Photoluminescence spectra of Dy -doped ZnO nanofibres showed an emission peak in the visible region that was free from any ZnO defect emission. Emissions at 480 nm and 575 nm in the Dy -doped ZnO nanofibres were the characteristic peaks of dopant Dy and implied efficient energy transfer from host to dopant. Luminescence intensity was found to be increased with increasing doping concentration and reduction in nanofibre diameter. Colour coordinates were calculated from photometric characterizations, which resembled the properties for warm white lighting devices.