a Department of Physics, United College of Engineering and Research, Prayagraj- 211010, India

^bDepartment of Electronics and Communication Engineering, Chandigarh Engineering College, Chandigarh Group of Colleges, Jhanjeri-140307, India

^cDepartment of Physics, Christ Church College, Kanpur-208001, India

^dDepartment of Electronics and Communication Engineering, Indian Institute of Information Technology, Prayagraj-211015, India

^eSchool of Materials Science and Technology, Indian Institute of Technology (BHU), Varanasi-221005, India

^fDepartment of Electronics Engineering, Yeungnam University, Gyeongsan- 38541, South Korea

This paper will present a comprehensive examination of unintentional hydrogen impurity in ZnO along with its stability and application. Results are based on the sampled synthesized by hydrothermal technique. The unique outcome of this study is co-existence of Zn and Hydrogen impurity including their complexes. Moreover, the existence and role of Zn and O di-vacancies also discussed. Synthesized nanoparticles analyzed by using XRD pattern, photoluminescence spectrum, Raman spectrum and positron annihilation experiment. The broad luminescence in visible region confirms the presence of different defects and impurities. Breakdown of the translation symmetry of the ZnO lattice also discussed based on Raman spectrum. Positron life time components provide the support to define the role of hydrogen impurity.