Conductivity Improvement of Spherical Nano-Crystalline ZnO:Bi/Indium Tin Oxide Layer for Low Cost of Semiconductor Devices

Abstract

In this work, rapid thermal annealing (RTA) was applied to multi-zinc oxide with doped bismuth layers (ZnO:Bi) on indium tin oxide substrate in the ambient atmosphere resulting in significant improvement of the conductive of multi- ZnO:Bi layers/ITO films. ITO is commonly used as conductive transparent electrodes for an electron transport layer (ETL) of perovskite solar cells. Spherical nano-crystalline ZnO:Bi film was obtained at 520 °C that inevitably affects unstable ITO conductivity. RTA process was subjected at varying conditions (700-930 °C for 20 s). It is found that the RTA process can obtain ZnO:Bi nanostructure, good optical property, and ITO conductivity improvement, simultaneously. The surface morphology of nc-ZnO:Bi films with a 10-20nm diameter size provide low reflectance and high transmittance at 3% and 90%, respectively, in the light wavelength between 250-850 nm. Highly conductive spherical nc-ZnO:Bi multilayers and stable conductivity ITO were obtained after RTA treatment. Thus, the high quality of such spherical nc-ZnO:Bi/ITO films could be used to produce ETL layer for further emerging solar cells and transparent contact electrodes for low-cost semiconductor devices.

Keywords:

• Conductive improvement
• ITO
• ZnO nanostructure
• nc-ZnO:Bi film
• rapid temperature annealing

Additional information

Funding

This work has been supported by Suranaree University of Technology (SUT) Research and Development Fund, Thailand. This work has been partially supported by the Research Network NANOTEC (RNN) program of the National Nanotechnology Center(NANOTEC), NSTDA, Ministry of Higher Education, Science, Research and Innovation (MHESI), Thailand.