Indium-gallium-zinc-oxide based mechanically flexible transimpedance amplifier

A mechanically flexible amorphous indium-gallium-zinc-oxide (a-IGZO) based transimpedance amplifier is demonstrated. The circuit consists of an a-IGZO thin-film transistor (TFT) and two resistors made of a-IGZO TFTs, integrated on a 50 mu m-thick Kapton substrate. A transimpedance (current-to-voltage) gain of 86.5 dB Omega and a cutoff frequency of 8.38 kHz are measured at a supply voltage of 5 V. The mechanical flexibility of the transimpedance amplifier is tested by bending the circuit to radii of 10 and 5 mm generating tensile strains of 0.3 and 0.5%, respectively. Bending the circuit to a radius of 5 mm decreases the gain by 1 dB Omega and increases the cutoff frequency by 1.45 kHz. The decreased gain is due to the increased electron mobility in the a-IGZO devices caused by the strain.