Flexible a-IGZO TFT amplifier fabricated on a free standing polyimide foil operating at 1.2 MHz while bent to a radius of 5 mm

We present flexible common source and cascode amplifiers fabricated on a free-standing plastic foil, using amorphous-Indium-Gallium-Zinc-Oxide (a-IGZO) TFTs with minimum channel lengths of 2.5 μm. Amplifiers are operated at a supply voltage V_DD of 5 V, and exhibit maximum cutoff frequencies f_C of 1.2 MHz. The circuits stay fully operational while bent to a tensile radius of 5 mm, and after 1000 cycles of repeated bending and re-flattening. To our knowledge, these are the fastest flexible oxide semiconductor based amplifiers.