Complete stress release in monolayer ALD-Al 2 O 3 films based on mechanical equilibrium homeostasis to realize a bending radius of 1 mm

Encapsulated Al 2 O 3 thin films prepared by atomic layer deposition have excessive stress, which is simply released by the pre-bending and heat treatment method and a flexible OLED with a radius of 1 mm is successfully prepared for the first time.