Thermal treatment for enhancing performance of NiO/Ag/NiO transparent conducting electrode fabricated via magnetron radio-frequency sputtering

A NiO/Ag/NiO (NAN) transparent conducting electrode (TCE) is fabricated using a low-cost magnetron-sputtering system. The effects of various thicknesses of the Ag intermediate layer and different annealing temperatures on the optical and electrical properties of the prepared TCEs are investigated comprehen-sively. A NAN TCE with a thin (8 nm) Ag layer demonstrates a slightly lower average transmittance than that with a 10 nm Ag layer because the thinner Ag layer appears as an isolated island structure, resulting in higher optical absorption. As the Ag thickness increases to 10 nm, the isolated islands become connected to each other and form a continuous thin film. As the Ag thickness increases, the carrier concentration and mobility increase and the formation of a continuous dense film, which decrease the resistivity and sheet resistance of the NAN TCE. The NAN TCE with a 14-nm intermediate Ag layer exhibits a sheet resistance of 3.67 Omega/sq, which is much lower than that (34 Omega/sq) of a single ITO electrode. The NAN TCE with a 10-nm Ag exhibits the highest figure-of-merit (FOM) than others. The annealing significantly increases the FOM from 2.5 x 10(-4) to 1.2 x 10(-2) Omega(-1), respectively, for the as-deposited NAN TCE with a 10-nm Ag layer and the NAN TCE annealed at 400 degrees C. However, the performance of NAN TCE degrades at higher annealing temperature (500 degrees C). (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A NiO/Ag/NiO (NAN) transparent conducting electrode (TCE) was fabricated using a low-cost magnetron-sputtering system. The study investigated the effects of different thicknesses of the Ag intermediate layer and various annealing temperatures on the optical and electrical properties of the prepared TCEs. Thinner Ag layers appeared as isolated island structures resulting in higher optical absorption, while thicker Ag layers formed continuous films leading to lower resistivity and sheet resistance.