A high quality ITO/PET electrode for flexible and transparent optoelectronic devices


High quality indium tin oxide/polyethylene terephthalate (ITO/PET) electrode with sheet resistance as low as 1.16 Ω/□ and the optical transmittance of 91 % at the wavelength of 600 nm was fabricated. The room-temperature radio frequency (RF) magnetron sputtering technique was used to deposit ITO thin film on PET substrate under low RF power without oxygen flow or post treatment. The remarkable value of 118.5 × 10−3 Ω−1 was achieved for the figure of merit in the 93 nm thick ITO thin film, due to the fine tuning of the sputtering parameters. An entirely Ohmic behavior was recorded for the ITO/PET electrode on the copper contacts suggesting that the product is highly capable for application in optoelectronic devices. The results of field emission scanning electron microscopy and atomic force microscopy demonstrated film consistency with a desired surface morphology giving a Rrms value of 2.073 nm. The elemental, chemical and phase analyses further revealed that the deposited ITO thin film on the PET substrate was pure and amorphous.