Superior switching behavior of liquid crystals on surface-modified compound oxide films

• HfYO alignment layers were grown on ITO-coated glass using solutions.
• HfYO alignment layers were analyzed by AFM, XRD, UV transmittance and XPS.
• HfYO alignment layer can be produced at low annealing temperature.
• Fast switching of LCs on HfYO films was achieved.
• The alignment mechanism was discussed in detail.

We demonstrate high-performance liquid crystal (LC) devices using alignment layers formed of solution-processed HfYO films that were subjected to ion-beam (IB) irradiation. IB irradiation entails the increment of the surface roughness and chemical modification of the surface. Our X-ray photoelectron spectroscopy (XPS) analysis revealed that IB irradiation also breaks oxygen bonds, and thereby creates oxygen vacancies with lattice displacement of the metal atoms. This variation stabilizes the homogeneous LC alignment. The LC cells formed using the IB-irradiated HfYO films with an intensity of 2200 eV yielded a rapid response time of 6.579 ms. Therefore, our fast switching application based on IB-irradiated HfYO films has great potential for application of display devices.