High Haze Ratio-Based ITO Films Prepared on Periodic Textured Glass Surfaces for Thin Film Solar Cells

Abstract

Light-trapping phenomenon is limited due to non-uniform surface structure of transparent conducting oxide (TCO) films. The proper control of surface structure with uniform cauliflower TCO films may be appropriate for efficient light trapping. We report a light-trapping scheme of SF6/Ar plasma-based textured glass surfaces for high root-mean-square (RMS) roughness and haze ratio of ITO films. It was observed that the variation in Ar flow ratio in SF6/Ar plasma during the inductive coupled plasma-reactive ion etching (ICP-RIE) process was an important factor to improve the haze ratio of textured glass. The SF6/Ar plasma textured glass showed low etching rates due to the presence of various metal elements, such as Al, B, F, and Na. The ITO films were deposited on SF6/Ar plasma-textured glass substrates showed the high RMS roughness (433 nm) and haze ratio (67.8%) in the visible wavelength region. The change in surface structure has a negligible influence on the electrical properties of ITO films. The TCO films deposited on periodic textured glass surfaces with high RMS roughness and haze ratio are proposed for high-efficiency amorphous silicon (a-Si) thin-film solar cells.