ZnO Doped with Bismuth in Case of In-Phase Behavior for Solar Cell Application

Zinc Oxide (ZnO) nanostructure thin films doped with bismuth atoms were initially achieved by spin coating preparation from zinc acetate gel on the fused quartz substrate. The optical and structural properties have been preliminary studied in order to obtain more understanding the optimized factors for transparent conductive oxides (TCOs) of thin film solar cell. The optical transmittance was higher than 90% in the visible range for all films. In addition, the optical band gap of the prepared films calculated by Tauc plot showed the change of lightly blue shift with a decrease in annealing temperature. The glancing incident X-ray diffraction result showed that the Bi doped in ZnO nanostructure thin films after annealing have polycrystalline hexagonal wurtzite structure and good preferential orientation along c-axis. This chemical characterization indicated that in-phase behavior occurred in low Bi dopant content between 0.2 - 1.0 atomic percentage Bi content, hence 1 atomic percentage of Bi content was uppermost to obtain preferential orientation in this study. However, the quality of the films surface was better due to the larger number of layers but the optical transmittance will be poorer. The tentative study in term of electrical behavior was investigated for application in TCO film of solar cell. The electrical property showed that more multi ZnO layers affected on an increase in the electrical conductivity of the films