Available online at www.sciencedirect.com ScienceDirect Materials Today: Proceedings 17 (2019) 261–265 www.materialstoday.com/proceedings 2214-7853 © 2019 Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the International Conference on Advanced Materials, Energy & Environmental Sustainability, ICAMEES2018 ICAMEES 18 Effect of Annealing on Structure, Optoelectronic and Photoresponsivity Properties of Sol-gel Prepared ZnO Nanoparticles Prashant Kumar Mishra 1 , Somaditya Sen 2,* , Ruhul Amin 3 , Sajal Biring 4 1, 2*, 3 Discipline of Physics, Indian Institute of Technology Indore, Khandwa Road, Indore - 453552, India 4 Dept. of Electrical Engg., Ming Chi University of Technology, New Taipei, Taiwan Abstract ZnO is successfully synthesized by sol-gel synthesis route. These are analyzed by XRD, FESEM, and UV Sensing measurements. XRD indicates a polycrystalline nature with appreciable crystallinity. Changes in band structure and defect states are also discussed. Defect states are found to increase with annealing temperature and hence increase in oxygen related defects also noticed. Photocurrent decreases with annealing temperature. It may have wide applications in UV-sensors, UV filters, ad UV absorptive membranes etc. © 2019 Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the International Conference on Advanced Materials, Energy & Environmental Sustainability, ICAMEES2018 Keywords: Sol-gel, Annealing, Defects, Oxygen vacancies, UV-sensing 1. Introduction ZnO is low cost chemically stable semiconductor material with excellent optoelectronic, sensing and morphological properties. Owing to this it has got diverse applications as in lasers, light-emitting diodes, nano-sensors, and solar cells [1]. ZnO is n-type with wide bandgap ~3.37 eV and, exciton binding energy ~60meV which makes it a competitive optoelectronic material to GaN [2-3].There are many reports on the thermal treatment of ZnO under various annealing conditions such as temperature, environments, to improve the optical properties of ZnO [4].In present work, structural, morphological, optoelectronic and photo-sensing characteristics have been studied for ZnO nanoparticles annealed at different temperatures. Effects of annealing on defects states, UV-sensing and co-relation between them are discussed.