High‐Speed, Flexible Electronics by Use of Si Nanomembranes

Traditionally, flexible electronics have addressed low or moderate operating frequency applications because the materials for flexible electronics, such as polymer and noncrystalline inorganic semiconductors, have poor electrical properties. Fast flexible electronics that operate at radiofrequencies (RFs) regime, particularly at microwave frequencies, could lead to myriad novel RF applications that conventional rigid solid-state electronics cannot easily fulfill. Single-crystalline semiconductor nanomembranes that can be released from various source wafers not only show very good flexibility and durability but also exhibit outstanding electrical properties that are equivalent to those of their bulk counterparts. These thin and flexible single-crystalline materials can furthermore be placed, via transfer-printing techniques, onto nearly any substrates, thus creating the opportunity to realize RF flexible electronics. In this chapter, we present various RF active devices made of semiconductor nanomembranes on plastic substrates such as flexible transistors and switches.