Transfer Printing of Photoactive Layer Enabling Efficient, Wearable, and Dual‐Function Organic Solar Cell Modules for a Wireless Healthcare Monitoring System

Abstract While transfer‐printing is a great technique for efficient film fabrication of many emerging devices on various substrates, its application in organic solar cells (OSCs) is rarely explored. Besides, it is highly challenging to fabricate a large‐scale production of a “dual‐function OSC module” that runs two‐objective functions simultaneously in a given single system. Through comprehensive investigation on the transfer‐printing feasibility of various π ‐conjugated organic materials, in addition to successful transfer‐printed OSC and flexible OSC module, implementation of dual‐function OSC modules via the transfer‐printing, in which two individual sub‐cell series based on dual‐purpose photoactive layers are separately integrated into a single system is showcased here. Moreover, the fabrication and operation of a wearable integrated self‐powered system for wireless healthcare monitoring with the wearable transfer‐printed dual‐function OSC module are also demonstrated. This study opens the door to fabricating OSCs with multi‐objective structures via the transfer‐printing technique, which enables the extra device‐level values for advanced energy‐related applications.