Synthesis, photoluminescence and CIE chromaticity of nanocrystalline Zn1-xCaxO (x=0.02&0.05)

2% and 5% Calcium doped ZnO nanocrystals have been synthesized using citrate-nitrate sol-gel route at 100°C and characterized by powder X-ray diffraction and Photoluminescence spectroscopic measurements. Analysis of XRD patterns confirmed that the two Ca doped ZnO samples crystallize in single phase wurtzite type nanocrystalline hexagonal structure without impurity. Photoluminescence spectra shows that Ca doping leads to reduction in the band gap energy and blue shift in the visible band emission. 2% Ca doped sample showed maximum emission in the red band and the 5% doped sample emits more in the orange band. The estimated values of colour correlated temperatures are found to be 2427K for 2% Ca and 2916K for 5% Ca doped ZnO, makes them suitable material for optoelectronic devices.