Cover Picture: Polymer Solar Cells with Micrometer‐Scale Engraved Active Nanolayers Fabricated by Pressing with Metal Molds (Energy Technol. 8/2014)

Micro-Mold Process for Plastic Solar Cells: A practical metal micro-mold technology, which is cost-effective and directly applicable for versatile roll-to-roll continuous processes for flexible plastic solar cells, is presented by realizing polymer solar cells with micro-engraved active layers featuring particular crystalline nanostructures in the engraved regions. The cover image shows the possible design of roll-to-roll systems with the micro-mold rolls for fabricating plastic solar cells with the embossed (engraved) active layers. The Full Paper on by Hwajeong Kim and Youngkyoo Kim of Kyungpook National University (South Korea) demonstrates that the micro-embossed metal mold could make clear micro-engraved patterns on the polymer:fullerene bulk heterojunction layers even at low temperatures (60 degree C), and the resulting polymer solar cells showed very good performance. The low-temperature metal-mold process reflects the important point that the present technology could be applied for various types of organic solar cells, whether or not their active layers are subject to the thermal annealing process, and this could have an impact on industrial manufacturing systems in the near future.