Effects of pH values on crystal growth and photoluminescence properties of ZnO hexagonal rods with cones

In this paper, we focus on the synthesis of zinc oxide (ZnO) hexagonal rods with cones by liquid precipitation routes, in which the pH values of the precipitation were tuned by controlling the volume of sodium hydroxide (NaOH). XRD and SEM results showed that the as-prepared ZnO nanostructures had a hexagonal wurtzite structure. The crystal faces were more inclined to grow along (100) direction than along (101) direction with the increase of pH values. The UV-vis spectrum indicated an extremely absorption in wave length of 380 nm close by. The as-synthesized materials achieved the spectral red shift around 610 nm excited by near ultraviolet light of 376 nm. The results revealed the possibility of utilizing the fluorescent powder to improve the properties of LEDs for future research on device fabrication.