A flexible transparent gas barrier film employing the method of mixing ALD/MLD-grown Al2O3 and alucone layers.

Wang Xiao,Chen Li Xiang,Duan Ya Hui,Chen Ping,Zhao Yi,Chen Zheng,Duan Yu,Yang Yong Qiang

doi:10.1186/s11671-015-0838-y

Wang Xiao, Chen Li Xiang + Show 6 more

Open Access

https://doi.org/10.1186/s11671-015-0838-y

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Abstract

Atomic layer deposition (ALD) has been widely reported as a novel method for thin film encapsulation (TFE) of organic light-emitting diodes and organic photovoltaic cells. Both organic and inorganic thin films can be deposited by ALD with a variety of precursors. In this work, the performances of Al2O3 thin films and Al2O3/alucone hybrid films have been investigated. The samples with a 50 nm Al2O3 inorganic layer deposited by ALD at a low temperature of 80°C showed higher surface roughness (0.503 ± 0.011 nm), higher water vapor transmission rate (WVTR) values (3.77 × 10−4 g/m2/day), and lower transmittance values (61%) when compared with the Al2O3 (inorganic)/alucone (organic) hybrid structure under same conditions. Furthermore, a bending test upon single Al2O3 layers showed an increased WVTR of 1.59 × 10−3 g/m2/day. However, the film with a 4 nm alucone organic layer inserted into the center displayed improved surface roughness, barrier performance, and transmittance. After the bending test, the hybrid film with 4 nm equally distributed alucone maintained better surface roughness (0.339 ± 0.014 nm) and barrier properties (9.94 × 10−5 g/m2/day). This interesting phenomenon reveals that multilayer thin films consisting of inorganic layers and decentralized alucone organic components have the potential to be useful in TFE applications on flexible optical electronics.

Highlights

Organic electronics is an emerging technology that has potential uses in highly efficient lighting, super-bright displays, novel photovoltaic devices, and integrated smart systems [1,2,3]
The alucone layer was divided into four equal parts in film C (9/1/9/1/9/1/9/1/ 9 nm). Both Al2O3 and alucone thin films were deposited by a LabNano 9100 Atomic layer deposition (ALD) system (Ensure Nanotech Inc., Beijing, China) at 80°C, and all pipes were heated to 120°C, while the pressure in the reaction chamber was 1.5 × 100 Pa
A similar molecular layer deposition (MLD) deposition rate was achieved at 3.8 Å/cycle at 80°C, which further indicates that MLD alucone is typically a bifunctional monomer for fast stepwise condensation polymerization and yield completely organic films

Summary

Introduction

Organic electronics is an emerging technology that has potential uses in highly efficient lighting, super-bright displays, novel photovoltaic devices, and integrated smart systems [1,2,3] It offers promising opportunities for the development of new products that utilize the special features of organic electronics such as flexibility, bendability, and transparency [4,5,6]. The gas barrier and mechanism performances were both optimized [20] upon Al2O3 samples incorporating a 4-nm transparent organic component of the same nominal thickness From this analysis, some important insights were determined, demonstrating that the performance of TFE with hybrid inorganic-organic structure could be optimized by prudent selection of certain design parameters

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Conclusion