Texturing of polydimethylsiloxane surface for anti-reflective films with super-hydrophobicity in solar cell application

This study utilized a Cu metal assisted chemical etching (MACE) method to produce an anti-reflection texture on poly dimethyl siloxane (PDMS). We measured the diffuse and total transmittance, total reflectance, and haze ratio to analyze the optical properties of the textured PDMS films, which were confirmed using finite-difference time-domain (FDTD) calculations. The anti-reflection textured PDMS films exhibited improved optical performance in the visible light region, owing to the light scattering and trapping effect, by improving the lateral surface area and aspect ratio of the micro/nanostructures. The average reflectance was 2.86% under optimal conditions. The optimized structures of the films also showed super-hydrophobicity (θCA≈155.2°). We applied the optimized film to perovskite photovoltaic solar cell devices and observed an enhanced short-circuit current density (Jsc) from approximately 21.95 to 24.06 mA/cm2 (∼9% increase). The improved Jsc increased the PCE to 17.11% (∼11% increase) in the MAPbI3 p-i-n structured devices. Based on the results, we confirmed that the superhydrophobic anti-reflection PDMS film can be used to overcome the limitation of light absorption in solar cell applications.