This book will provide a good understanding to readers about the chemical synthesis process of un-doped and doped ZnO nanoparticles. The various characterization has been done which emphasize to optoelectronic application on the basis of band gap tuning. And it has an immense application in DMS materials also. The additional information includes in the APPENDICES-A & B which might be useful for synthesis and the energy band gap calculation with theoretical reference.