Effect of Annealing on the Ultraviolet Sensing Properties of the Chemically Synthesized n-Type Nanodots of ZnO

Isolated nanodots of ZnO of at least 100 nm in size were deposited on transparent conducting substrate (Indium Tin Oxide coated quartz) by aqueous chemical growth technique. The nanodots have polycrystalline character and their crystallinity improves due to annealing in vacuum and oxygen atmosphere. The ultraviolet sensing property of the ZnO nanodot was investigated by current-voltage measurement. Under ultraviolet irradiation, the photo current was observed to be higher for the nanodots having higher volume density of point defects.