Aluminum Grid Reduce the Sheet Resistance of Indium Tin Oxide Thin Films

The efficiency of large-area perovskite cell modules has been about 10% lower than that of smallarea cells, in which the transverse resistance of transparent conductive oxide(TCO) electrode is the main factor for the increase of series resistance. In this paper, grooves with a depth of 1-2 μm and a minimum transverse width of 10 μm were prepared on ultra-white glass by wet etching, and then aluminum was evaporated, and Indium Tin Oxide(ITO) films were deposited by RF sputtering. By adjusting the etching parameters, a good aluminum grid shape was obtained. The results show that the average transmittance of ITO thin films with the aluminum grid is about 3.5% lower than that of ITO thin films without the aluminum grid. The transverse resistance is significantly ameliorated from 17.4 to 2.4 Ω, which may be further reduced by the future etching thickness adjustment and contribute to the significant improvement of the horizontal electron-collection ability in ITO thin films. This work makes it possible for large-scale industrial applications in glass-based thin-film solar cells.