Flexible metal–insulator–metal capacitors on polyethylene terephthalate plastic substrates

Realization of flexible electronic devices on polyethylene terephthalate flexible plastic substrates is reported. Metal–insulator–metal capacitors have been fabricated using radio frequency sputtered deposited thin films of Nb 2 O 5 on the flexible substrate. Good electrical characteristics have been obtained in terms of quadratic voltage coefficient of capacitance, high capacitance density (∼ 11 fF µm −2 ), high dielectric constant (∼37) and low dissipation factor (<0.1). Besides, in repetitive bending test, the devices show excellent electrical stability and high mechanical flexibility due to the high ductility of niobium and low-temperature processing used in this study.