Conclusion
In summary, Co 2+ ions doped ZnO nanopow der was synthesized successfully by using single step solid state reaction method by sonication method. From powder X-ray diffraction data, the crystal structure belongs to hexagonal and average crystallite size was evaluated. The doped Co 2+ ions entered in the host ZnO lattice at octahedral coordinatio n without disturbin g the hexagonal structure of ZnO. Optical absorption and EPR spectra also confirmed that the doped Co 2+ ions occupied at octahedral site symmetry for which crystal field (Dq) and inter-electroni c repulsion (B, C) parameters are evaluated. By correlating EPR and Optical absorption data, the evaluated bonding parameter suggested that there
exists a covalent bond between the doped Co 2+ ions and its ligands. PL spectrum showed characterist ic ZnO emission bands in UV and blue regions. The evaluated CIE color coordinates indicated that this material can be used for blue light emitting devices. The formation of Zn AO bonds was also confirmed by FT-IR spectral data and showed the vibrational bands in the region of 400–600 cm 1.