Dot-like Periodic Patterning of Fluorine-doped Tin Oxide (FTO) Thin Films using Direct Laser Interference Patterning (DLIP) for Photovoltaic Applications

HERMAN HEFFNER; JULIUS BRUNNER; ANDRÉS FABIÁN LASAGNI; YANA VAYNZOF

Frankfurt am Main

Congreso; FEMS EUROMAT 2023; 2023

Deutsche Gesellschaft für Materialkunde (DGM)

Various mechanisms can be optimized to reach the efficiency limit in solar cells, as stated by Shockley and Queisser. Among these mechanisms, one crucial aspect is the optimization of the transparent conductive oxide (TCO) located in front of the device. The TCO is responsible for the extraction of photogenerated carriers and serves as a window for the Sun's light. Moreover, generating periodic micro- and nanostructures on the surface of TCOs could lead to an overall increase in transmittance and surface area, potentially resulting in enhanced efficiency. In this study, direct laser interference patterning (DLIP) was employed to modify fluorine-doped tin oxide (FTO) thin films. Afterward, these were used as TCOs for perovskite quantum dots (QD) solar cells.The results reveal dot-like surface periodic microstructures with an approximate spatial period of 1.4 μm (see Figure 1a) and an average structure depth between 15 and 100 nm depending on the fluence level. This led to an increase in the spread of incident light and the total transmittance. To quantify the effect of this patterning on the overall performance on optoelectronic devices, these structured films were employed in perovskite QD solar cells. Figure 1b illustrates the obtained external quantum efficiency, showing an enhancement for most of the 350-700 nm spectrum, which can be attributed to the periodic micro- and nanostructures generated with the DLIP technique. Finally, the obtained efficiency resulted in a relative increase of 18% on average when compared to solar cells that utilized regular FTO.