A Refined Dual-Fiber Network Morphology as Printable Hole Transport Layers for High-Performance Perovskite Solar Mini-Modules

In the contemporary preparation of perovskite solar cells (PSCs), the prevalent issue of hole transport layers (HTLs) materials is frequently incompatible with large-area deposition techniques. As the area increases, this results in nonuniform preparation of the HTLs, which significantly reduces the efficiency and reliability of the device at the module level. To tackle this significant challenge, we propose a strategy for a dual-fiber network structure based on polymer HTLs. This strategy involves the use of organic solar cell polymer donor material (PM6) and poly(3-hexylthiophene) (P3HT), which are spontaneously interwoven into micron-sized fiber crystals to establish efficient carrier transport channels. This unique structure not only accelerates charge extraction but also takes advantage of the inherent benefits of polymers, such as excellent printability and homogeneous film formation while enhancing the protection of the perovskite layers. The resulting devices demonstrate a V_OC of 1.18 V and a champion PCE of 24.90%, which is higher than the pristine devices (the PCE is 22.87%). Moreover, due to the improved printing characteristics, the PSMs prepared by blade-coating also demonstrate a high PCE of 15.15% within an aperture area of 100 cm². Additionally, this strategy significantly improves the operational stability, thermal stability, and humidity stability of the devices.