Al₂O₃/ZrO₂ Nanolaminates as Ultrahigh Gas‐Diffusion Barriers—A Strategy for Reliable Encapsulation of Organic Electronics

Abstract

Highly efficient gas‐diffusion barriers based on nanolaminates of alternating Al2O3 and ZrO2 layers grown at 80 °C by atomic‐layer deposition are presented. Ultralow water‐vapor permeation rates are reported, and a dramatic reduction of statistical defects on larger areas was found compared to single Al2O3 layers. This study provides a concept for the encapsulation of organic optoelectronic devices.

Holmium and titanium oxide nanolaminates by atomic layer deposition

“…O 3 was used as an oxygen precursor. The O 3 concentration output of the generator was ~ 100 g/m 3 . Ho 2 O 3 layers were deposited at 300 °C using the ALD process based on Ho(thd) 3 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionato) and O 3 [27,29].…”

“…The O 3 concentration output of the generator was ~ 100 g/m 3 . Ho 2 O 3 layers were deposited at 300 °C using the ALD process based on Ho(thd) 3 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionato) and O 3 [27,29]. TiO 2 films were grown using an ALD process based on titanium tetra- A Sopra GES-5E variable angle spectroscopic ellipsometer was used to determine the thickness (d) and optical properties (n, k) using 'Winelli II' software.…”

“…Especially important industrially are the ZrO 2 -Al 2 O 3 -ZrO 2 structures [24] used in dynamic random access memory cells. Nanolaminates may also perform as gas-diffusion barriers for reliable encapsulation of organic electronics [3], show long term durability as corrosion-protective layers [17], act as optical filters tuning the reflection from silicon substrate [11] or as hard X-ray mirrors [15]. Nanolaminates with large number of interfaces may also have reduced cross-plane thermal conductivity compared to that in chemically homogeneous films [1].…”

“…Nanolaminates of single oxides may be grown using different physical and chemical techniques, such as electron beam evaporation [13], sputtering [4], pulsed laser deposition [6] or, as apparently the most controlled method, atomic layer deposition (ALD) [1][2][3]5,7,[9][10][11][12][14][15][16][17][18][22][23][24]26]. Studies on ALD-grown nanolaminates containing rare earth oxides have so far been quite scarce [21,22], though, and none has been grown using Ti and Ho oxides as constituents.…”

“…HfO 2 -Al 2 O 3 [1], ZrO 2 -Al 2 O 3 [2][3][4][5][6], ZrO 2 -Y 2 O 3 [7], ZrO 2 -SiO 2 [7], HfO 2 -Al 2 O 3 [8,9], TiO 2 - [18,20], ZrO 2 -Er 2 O 3 [21], ZrO 2 -Gd 2 O 3 [22], and TiO 2 -Cr 2 O 3 [23].…”