Liquid glass, a photo-curable amorphous silica nanocomposite, recently demonstrated groundbreaking capabilities as a transparent fused silica glass that can be structured in arbitrary geometries [1,2]. The ability to process high-quality glass like a polymer, including the use of 3D printing techniques, opens up new routes to integrate optical microstructures for improved light harvesting in solar module architectures .
Optical microstructures increase the power conversion efficiency of solar modules by improved light in-coupling or by guiding light into the active area of solar modules. We investigate freeform surface cloaks that effectively increase the active area of solar modules  and micro-cones that reduce front side reflection and trap light in solar modules . The first prototypes of encapsulated freeform surface cloaks have demonstrated a significant increase in generated current density of around 6% relative . Yet, embedding of freeform surface cloaks into the architecture of conventional solar modules relies on encapsulation with various polymer layers and a glass cover by plasma bonding. In this contribution, we will present the direct integration of optical microstructures, represented by the above outlined concepts, into transparent fused silica glass covers. This approach provides both a higher optical quality of the module encapsulation and an improved compatibility of optical microstructures with the fabrication process of common solar modules.
In summary, we demonstrate a new route for integrating optical microstructures into the architecture of solar modules by the example of embedded freeform surface cloaks and micro-cones. This highlights the great opportunities 3D shaping of liquid glass brings to the world of photovoltaics.
 F. Kotz, K. Arnold, W. Bauer, D. Schild, N. Keller, K. Sachsenheimer, T. M. Nargang, C. Richter, D. Helmer, and B. E. Rapp, "Three-dimensional printing of transparent fused silica glass," Nature 544, 337–339 (2017).
 F. Kotz, K. Plewa, W. Bauer, N. Schneider, N. Keller, T. Nargang, D. Helmer, K. Sachsenheimer, M. Schäfer, M. Worgull, C. Greiner, C. Richter, and B. E. Rapp, "Liquid Glass: A Facile Soft Replication Method for Structuring Glass," Adv. Mater. 28, 4646–4650 (2016).
 F. Kotz, N. Schneider, A. Striegel, A. Wolfschläger, N. Keller, M. Worgull, W. Bauer, D. Schild, M. Milich, C. Greiner, D. Helmer, and B. E. Rapp, "Glassomer—Processing Fused Silica Glass Like a Polymer," Adv. Mater. 30, 1–5 (2018).
 M. F. Schumann, M. Langenhorst, M. Smeets, K. Ding, U. W. Paetzold, and M. Wegener, "All-Angle Invisibility Cloaking of Contact Fingers on Solar Cells by Refractive Free-Form Surfaces," Adv. Opt. Mater. 5, 1700164 (2017).
 S. Dottermusch, R. Schmager, E. Klampaftis, S. Paetel, O. Kiowski, K. Ding, B. S. Richards, and U. W. Paetzold, "Micro-cone textures for improved light in-coupling and retroreflective light-trapping at the front surface of solar modules," in subsmission (2018).
 M. Langenhorst, M. F. Schumann, S. Paetel, R. Schmager, U. Lemmer, B. S. Richards, M. Wegener, and U. W. Paetzold, "Freeform surface invisibility cloaking of interconnection lines in thin-film photovoltaic modules," Sol. Energy Mater. Sol. Cells 182, 294–301 (2018).