Enhanced light-trapping capabilities of FTO and ITO Thin Films using Direct Laser Interference Patterning (DLIP) for Photovoltaic Applications

The optimization of various mechanisms is essential to reach the efficiency limit in solar cells, as highlighted by Shockley and Queisser[1]. One critical aspect involves enhancing the transparent conductive oxide (TCO) positioned at the front of the device. The TCO plays a crucial role in extracting photogenerated carriers and acts as a window for the Sun's light. Additionally, introducing periodic micro- and nanostructures on TCO surfaces has the potential to increase transmittance and surface area, leading to improved efficiency[2–5]. In this research, direct laser interference patterning (DLIP) was employed to modify thin films of fluorine-doped tin oxide (FTO) and indium tin oxide (ITO), which were subsequently utilized as TCOs for perovskite solar cells.
Results reveal dot-like periodic sub-microstructures with an approximate 700 nm spatial period, increasing incident light spread and total transmittance. These structured films improved perovskite solar cell performance, demonstrating the positive impact of the generated patterning in the light-trapping capabilities. Additionally, the increase in effective surface area might lead to a more efficient charge transfer in the interface between FTO/ITO and SnO2.