Development of Indium Tin Oxide Stack Layer Using DC and RF Sputtering for Perovskite Solar Cells
Indium tin oxide (ITO) films were used as transparent conductive oxide (TCO) layers in perovskite solar cells (PSCs). Generally, the commercial ITO film-coated glass substrate has good electrical properties and a film thickness of around 340 nm but low transmittance in long wavelength regions of 750-1200 nm. The enhancement of light transmittance by the ITO stack layer was developed. Direct current (DC) sputtering with the oxygen-argon (O2-Ar) gas mixture deposited the first ITO layer on a soda-lime glass substrate. Radio frequency (RF) sputtering with the Ar gas deposited in the second ITO layer. By optimizing the deposition conditions, the ITO stack layer has a total film thickness of around 330 nm, with a higher light transmittance of about 24% in the wavelength range of 750-1200 nm compared to the reference ITO (commercial). By using the ITO stack layer as a substrate for perovskite solar cells, the ITO stack layer structure of the DC:RF (1:1) has the highest efficiency compared to ITO film deposited from DC, RF, and reference ITO, which mainly from the increasing short current density (Jsc) of the solar cell. Applying an ITO stack layer for a perovskite solar cell achieved a power conversion efficiency of 14.9%.
Keywords: Indium tin oxide, ITO stack layer, Perovskite solar cell