Hydrogen behavior and microstructural evolution in flexible IGZO thin films under stress

In this study, we investigated the effect of mechanical stress on hydrogen diffusion in flexible amorphous InGaZnO (a-IGZO) thin films and the resulting microstructural changes. The cyclic bending test under different curvature radii (R) revealed significant morphological evolution and bond state changes in IGZO thin films. As the curvature radius decreases from 20 mm to 5 mm, the surface of the sample gradually becomes rough and cracks appear. Simultaneously, changes in nanoscale topological structure and chemical composition exhibit stronger hydrogen diffusion and structural relaxation: The oxygen-hydrogen (O-H) bond content increased from 19 % to 55 %, while the metal-oxygen (M − O) bond content decreased from 50 % to 28 %. The M − H content increased, and In-H related structures underwent transformation. The radius of gyration (R_g) increasing from 1.652 nm to 1.812 nm. These results provide quantitative insights into the stability and performance of IGZO-based flexible electronic devices under mechanical deformation.