@article{JaegerTejadaBerwigetal., author = {J{\"a}ger, Klaus and Tejada, Alvaro and Berwig, Sebastian and Hammerschmidt, Martin and Tockhorn, Philipp and Albrecht, Steve and Becker, Christiane}, title = {Optical Simulations of Nanotextured All-Perovskite Tandem Solar Cells}, series = {Advanced Theory and Simulations}, volume = {8}, journal = {Advanced Theory and Simulations}, number = {1}, issn = {2513-0390}, doi = {10.1002/adts.202400724}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-19640}, pages = {9}, abstract = {This numerical study investigates, how textures at various locations of all-perovskite tandem solar cells affect their optical performance. For this, hexagonal sinusoidal textures with 750 nm period and aspect ratios (height-to-period) of 27\% (moderate) and 54\% (pronounced) are considered. The optical simulations are performed with the finite element method and an algorithm to correct for the thick glass superstrate. The complex refractive index data of the wide-bandgap (WBG) and narrow-bandgap (NBG) perovskites with spectroscopic ellipsometry is determined. Texturing between the glass superstrate and the WBG perovskite top cell has an antireflective effect across the whole wavelength region. In contrast, texturing between the WBG perovskite top cell and the NBG perovskite bottom cell has no additional effect for a moderate texture but leads to light trapping in the NBG perovskite for a pronounced texture. Moderate texturing between the NBG perovskite absorber and the metal back contact leads to light trapping in the NBG perovskite but also excites surface plasmons in the copper back contact. Dielectric interlayers between the NBG perovskite and the metal back contact can reduce the plasmonic absorption losses. Texturing potentially allows to increase the current-matched short-circuit current density beyond 17 mA  cm-2.}, subject = {ellipsometry}, language = {en} } @article{WinartoSutterTockhornetal., author = {Winarto, Hanifah and Sutter, Johannes and Tockhorn, Philipp and Škorjanc, Viktor and Patil, Pramila and Berwig, Sebastian and Zimmermann, Lea and Mart{\´i}nez-Denegri, Guillermo and Albrecht, Steve and Becker, Christiane}, title = {Periodic Inverted Micropyramids for Optically Optimized Fully Textured Solution-Processed Perovskite Solar Cells}, series = {Solar RRL}, volume = {9}, journal = {Solar RRL}, number = {23}, publisher = {Wiley}, issn = {2367-198X}, doi = {10.1002/solr.202500613}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-22175}, pages = {10}, abstract = {Optical performance of perovskite-based solar cells can be enhanced by utilizing fully textured interfaces. However, solution processing of perovskite films on textured surfaces is a nonstraightforward and challenging process, particularly if optically most efficient micrometer-sized textures are used. In this work, we present fully textured solution-processed perovskite solar cells on periodic inverted micropyramids. The textures have a period of 4 μm with varying pyramid depths and are fabricated by wet-chemical etching of silicon with subsequent replication on glass substrates using nanoimprint lithography. Inverted pyramids are shown to enable low reflectance similar to random micropyramids on silicon. Additionally, they are able to confine perovskite precursor solution within its structure during spin coating, resulting in a conformal, fully textured perovskite film. We demonstrate that the resulting fully textured single-junction perovskite solar cells feature a reduced reflection loss of up to 1.2 mA/cm 2 in short-circuit current density. Moreover, we observe that the amount of lead iodide in the perovskite precursor solution crucially impacts growth and nonradiative recombination losses of the fully textured perovskite solar cells on inverted micropyramids. Finally, we prove the versatility of our approach by also demonstrating conformal coating with slot-die coating, which is a scalable process considered for industrial application.}, subject = {Solar cells}, language = {en} }