Perovskite microcells fabricated using swelling-induced crack propagation for colored solar windows.

Perovskite microcells have a great potential to be applied to diverse types of optoelectronic devices including light-emitting diodes, photodetectors, and solar cells. Although several perovskite fabrication methods have been researched, perovskite microcells without a significant efficiency drop during the patterning and fabrication process could not be developed yet. We herein report the fabrication of high-efficiency perovskite microcells using swelling-induced crack propagation and the application of the microcells to colored solar windows. The key procedure is a swelling-induced lift-off process that leads to patterned perovskite films with high-quality interfaces. Thus, a power conversion efficiency (PCE) of 20.1 % could be achieved with the perovskite microcell, which is nearly same as the PCE of our unpatterned perovskite photovoltaic device (PV). The semi-transparent PV based on microcells exhibited a light utilization efficiency of 4.67 and a color rendering index of 97.5 %. The metal-insulator-metal structure deposited on the semi-transparent PV enabled to fabricate solar windows with vivid colors and high color purity.

High-Resolution Spin-on-Patterning of Perovskite Thin Films for a Multiplexed Image Sensor Array.

Inorganic-organic hybrid perovskite thin films have attracted significant attention as an alternative to silicon in photon-absorbing devices mainly because of their superb optoelectronic properties. However, high-definition patterning of perovskite thin films, which is important for fabrication of the image sensor array, is hardly accomplished owing to their extreme instability in general photolithographic solvents. Here, a novel patterning process for perovskite thin films is described: the high-resolution spin-on-patterning (SoP) process. This fast and facile process is compatible with a variety of spin-coated perovskite materials and perovskite deposition techniques. The SoP process is successfully applied to develop a high-performance, ultrathin, and deformable perovskite-on-silicon multiplexed image sensor array, paving the road toward next-generation image sensor arrays.