Enhancement in the optical transmittance of zno:al powders by si co-doping

(Al, Si)-codoped ZnO powders with a constant molar ratio of Zn:Al (99:1) and various molar ratios of Si:Al (0-0.02) were synthesised by a sol-gel process and characterised by X-ray diffraction, field emission scanning electron microscopy, and UV-vis and luminescent spectrophotometry. The experiments indicated that the powders had random orientation and a slightly larger average particle size that increased with increasing Si proportion. The Mo doping resulted in the enhancement of transmittance in the UV-visible light range and the widening of the bandgap. Optimal efficiency appeared at a molar ratio of Si:Al-0.01, and Si doping resulted in the formation of a new emission centre and the enhancement of the emissions in range of visible light.