Investigating the annealing effect on the conventional growth of ZnO nanorod through electrical characterization

Abstract

Zinc oxide nanorods was synthesized by using hydrothermal growth due to simplicity and involve low temperature processing that is 930C. Low temperature processing is very essential for ZnO nanorod synthesis because defect on developing nano-device can be avoided. Development of nano-device with minimal defect is essential to ensure that the performances of the nano device is optimum for sensing bio-molecular substances. Zinc oxide has become the most remarkable choice among other metal oxides semiconductor due to many criteria such as economical cost, unique physical and electrical properties and biocompatible. Initially, ZnO thin films was prepared by using sol gel method. The ZnO seed solution was prepared using conventional sol-gel route. Zinc oxide solution was prepared in two different solvents which are isopropanol (IPA) and methanol (MeOH) in order to investigate the influence of solvent to the quality of ZnO nanorods. MEA, the sol stabilizer was added to the solution for the following 2 hours. Aluminum IDE electrode was deposited on the silicon wafer sample <;100> using traditional wet etching method. Positive photoresist (PR) was coated on the silicon wafer and followed with soft back for 90 seconds. IDE pattern transfer was done by exposing UV light (365nm) onto the PR for 10 seconds. After that, developing and etching process occurred for pattern transfer the IDE electrode onto the silicon wafer. The prepared seed solution was coated on silicon wafer by using speed coating method. Some of the coated samples underwent annealing process at temperature 2000C for 2 hours. The annealed and non-annealed sample undergoes hydrothermal growth method to synthesize ZnO nanorods. The synthesized nanorods underwent I-V test and capacitances to investigate the electrical behavior of ZnO nanorods. The annealed ZnO nanorods provided higher current, which was 900μA, as compared the non-annealed ZnO nanorods which was only 55 μA.