Ultrathin Crystalline Silicon Nano and Micro Membranes with High Areal Density for Low‐Cost Flexible Electronics

Abstract Ultrathin crystalline silicon is widely used as an active material for high‐performance, flexible, and stretchable electronics, from simple passive and active components to complex integrated circuits, due to its excellent electrical and mechanical properties. However, in contrast to conventional silicon wafer‐based devices, ultrathin crystalline silicon‐based electronics require an expensive and rather complicated fabrication process. Although silicon‐on‐insulator (SOI) wafers are commonly used to obtain a single layer of crystalline silicon, they are costly and difficult to process. Therefore, as an alternative to SOI wafers‐based thin layers, here, a simple transfer method is proposed for printing ultrathin multiple crystalline silicon sheets with thicknesses between 300 nm to 13 µm and high areal density (>90%) from a single mother wafer. Theoretically, the silicon nano/micro membrane can be generated until the mother wafer is completely consumed. In addition, the electronic applications of silicon membranes are successfully demonstrated through the fabrication of a flexible solar cell and flexible NMOS transistor arrays.