Highly transparent and flexible polyimide/ZrO2 nanocomposite optical films with a tunable refractive index and Abbe number.

In this study, novel thermally stable zirconia-containing polyimides (PI/ZrO2) with excellent optical properties have been prepared successfully. The obtained flexible PI/ZrO2 hybrid films revealed excellent optical transparency, a tunable refractive index and an Abbe number up to 1.804 and 32.18, respectively, which are crucial for optical devices. In addition, the PI/ZrO2 hybrid films also exhibit a higher Abbe number and transparency in the visible light region due to a larger energy band gap of ZrO2 than the corresponding PI/TiO2 system.