@article{SchaibleWinartoŠkorjancetal., author = {Schaible, Jonas and Winarto, Hanifah and Škorjanc, Viktor and Yoo, Danbi and Zimmermann, Lea and J{\"a}ger, Klaus and Sekulic, Ivan and Schneider, Philipp-Immanuel and Burger, Sven and Wessels, Andreas and Bl{\"a}si, Benedikt and Becker, Christiane}, title = {Optimizing Aesthetic Appearance of Perovskite Solar Cells Using Color Filters}, series = {Solar RRL}, volume = {9}, journal = {Solar RRL}, number = {2}, issn = {2367-198X}, doi = {10.1002/solr.202400627}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-20339}, pages = {13}, abstract = {The significance of color aesthetics in photovoltaic (PV) modules gains importance, especially in design-centric applications like building-integrated PVs. Color filters based on distributed Bragg reflectors, consisting of alternating thin-film layers of different refractive indices, can modify the appearance of standard silicon modules. This approach is also extended to optimize the color appearance of emerging PV technologies such as perovskite solar cells, which typically exhibit a less appealing gray-brownish appearance. In this contribution, perovskite solar-cell stacks combined with MorphoColor color filters are presented. Angular-resolved reflectance simulations based on wave optics and ray tracing with experimental data are validated, and the color appearance from various viewing angles is evaluated. Additionally, the impact of individual layers on color appearance and the maximum achievable short-circuit current density in the perovskite solar cell is investigated. By applying Bayesian optimization, the color distance is minimized to the targeted appearance. Tailoring the bridging layers between the color filter and the perovskite solar cell is found to strongly influence the color impression due to the coherently combined color filter and perovskite solar cell. The presented color optimization concept allows to customize the aesthetics of emerging PV thin-film technologies such as perovskite solar cells.}, language = {en} } @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} }