Growth kinetics of ZnO nanocrystallites: Structural, optical and photoluminescence properties tuned by thermal annealing

► ZnO nanocrystallites were grown by sol-gel spin coating. ► The size of the nanocrystallites were controlled by thermal annealing. ► Growth kinetics is understood by LSW theory of Ostwald ripening and activation energy of growth of nanocrystallites is determined. ► The structural, optical and photoluminescence properties are tuned and understood by controlling the size of nanocrystallites.