Morphology regulation of TiO_2 thin film by ALD growth temperature and its applications to encapsulation and light extraction

摘要

As a multi-functional material, TiO_2 thin film has been widely studied and applied in display, photocatalysis, solar cells and other fields. In this work, TiO_2 thin films were prepared using atomic layer deposition, and their morphology was successfully regulated by the growth temperature. It was found that TiO_2 film prepared at low temperature was amorphous, uniform and dense, with great barrier property, which can be used for encapsulation. Crystalline TiO_2 nanoparticles with anatase phase appeared at higher temperature than 150 °C, whose amount increased with the growth temperature. The crystalline TiO_2 particles can be used as templates to prepare randomly textured nano-patterns, which were proved to be able to improve the light extraction efficiency of photoelectric devices. Specifically, the luminance efficiency of the QLED with the nano-patterns formed by the crystalline TiO_2 particle prepared at 200 °C and 250 °C were increased by 24.07% and 30.44%, respectively.