A Study of Al2O3/MgO Composite Films Deposited by FCVA for Thin-Film Encapsulation

Heng Yuan; Yifan Zhang; Qian Li; Weiqing Yan; Xu Zhang; Xiao Ouyang; Xiaoping Ouyang; Lin Chen; Bin Liao

doi:10.3390/ma16051955

A Study of Al₂O₃/MgO Composite Films Deposited by FCVA for Thin-Film Encapsulation

Materials (Basel). 2023 Feb 27;16(5):1955. doi: 10.3390/ma16051955.

Authors

Heng Yuan^{1

2}, Yifan Zhang^{1

2}, Qian Li^{1

2}, Weiqing Yan^{1

2}, Xu Zhang^{1

2}, Xiao Ouyang^{1

2}, Xiaoping Ouyang^{1

2}, Lin Chen², Bin Liao^{1

2}

Affiliations

¹ College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China.
² Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China.

Abstract

Al₂O₃ and MgO composite (Al₂O₃/MgO) films were rapidly deposited at low temperatures using filtered cathode vacuum arc (FCVA) technology, aiming to achieve good barrier properties for flexible organic light emitting diodes (OLED) thin-film encapsulation (TFE). As the thickness of the MgO layer decreases, the degree of crystallinity decreases gradually. The 3:2 Al₂O₃:MgO layer alternation type has the best water vapor shielding performance, and the water vapor transmittance (WVTR) is 3.26 × 10^-4 g·m^-2·day^-1 at 85 °C and 85% R.H, which is about 1/3 of that of a single layer of Al₂O₃ film. Under the action of ion deposition, too many layers will cause internal defects in the film, resulting in decreased shielding ability. The surface roughness of the composite film is very low, which is about 0.3-0.5 nm depending on its structure. In addition, the visible light transmittance of the composite film is lower than that of a single film and increases with the increase in the number of layers.

Keywords: Al2O3; FCVA; MgO; thin-film encapsulation.

Grants and funding

This research was funded by the National Natural Science Foundation Joint Fund Key Project (Grant No. U1865206), National Science and Technology Major Project (Grant No. J2019-VIII- 0003-0164), China Postdoctoral Science Foundation (No. 2022M710415), National Natural Science Foundation of China (No. 12205016), and Fundamentals Research Funds for the Central Universities (No. 2021NTST14).