Solution-processed, flexible, and highly transparent ZrO2:PVP hybrid dielectric layer

Organic-inorganic hybrid dielectric layers have attracted extensive attention due to their ability to simulta-neously improve the relative dielectric constant (k) and mechanical properties of gate dielectric layers, and have great potential in flexible and wearable displays. This paper reports a low-temperature deposition method of high-quality Zirconium (IV) dioxide (ZrO2) and Polyvinylpyrrolidone (PVP) hybrid gate dielectric layers by sol -gel method. The hybrid films have a smooth morphology, low roughness, high transmittance of 95% in the wavelength range higher than 320 nm, and an optical bandgap of up to 5.63 eV. The leakage current density (J) of the hybrid film is as low as 6.85 x 10-6 A/cm2 at 1 MV/cm, and no breakdown phenomenon was observed when electric fields up to 2 MV/cm were applied. In addition, enhanced interface polarization occurred between PVP and ZrO2, thereby increasing the hybrid film's k, resulting in a high-k (32.3 at 1 kHz). The fabricated films also exhibited good flexibility and maintain excellent insulation after 200 times of bending with a radius of 10 mm. Finally, low operating voltage thin film transistors (TFTs) using these high k ZrO2:PVP dielectrics were obtained and a threshold voltage of 0.05 V and on/off current ratio of 1.24 x 105 were measured. The results demonstrate that the fabricated hybrid films are ideal gate dielectric materials for flexible wearable and low power consumption devices.

Automated summary

This paper presents a low-temperature deposition method for high-quality ZrO2:PVP hybrid gate dielectric layers, which possess advantages such as high optical bandgap, low leakage current density, and enhanced interface polarization, making them suitable for flexible wearable and low power consumption devices.