| dc.description.abstract | In this study, the influence of Ni2+ concentration doped on the absorbance and photocurrent of the ZnO thin films under different parameters is investigation. The ZnO thin films were prepared by chemical bath deposition (CBD) method, which has several advantages such as : lower cost, low temperature operation, and simple process. Since the undoped-ZnO films have a large energy gap of 3.2eV, they can not absorb the visible light. In order to enhance the absorption of the visible light and promote the photocurrent, Ni2+ ions are doped into ZnO films to add the middle energy gap.
In the experiment, the influence of various kinds of parameter on the properties of undoped-ZnO is investigated to obtain the optimal working parameters. Under this optimal condition, films are doped with Ni2+ ion of 4%, 6%, 8% and 10%, respectively. The properties of the films like morphology, absorbance and photocurrent characteristic are observed and analyzed. For experiment results, it is found that the optimal condition occurs when R is 2.25, pH is 13, the bath deposition temperature is 70℃, the total bath deposition time is 9h within which a 1h deposition is repeated and heat treatment is performed at every 3h, heat treatment temperature is 450℃, and haet treatment time is 2h with increasing and decreasing temperature rate of 3℃/min. The ZnO films doped with 0.01M 8% Ni2+ in above parameters has the best absorbance and photocurrent values. The maximun absorbance can reach 1.2 above, and the maxinum photocurrent value can also reach 0.02 mA/cm2 when the bias potential was 0.3 V. | en_US |