Spotless hybrid thin-film encapsulation stack for organic light-emitting diodes on organic foils

In order to protect a flexible OLED on plastic foil against water from the ambient atmosphere a top and bottom thin-film encapsulation (TFE) is necessary. A TFE stack SiN-OCP-SiN with getter in OCP results in excellent shelf lifetime. However, the getter particles result in light scattering that is lost upon water ingress in the stack. As a...

High Temperature Thin-Film Barriers for Foldable AMOLED Displays

We present a thin-film dual-layer bottom barrier on PI that is compatible with 350°C backplane processing for OLED displays. We demonstrate OLEDs that survive bending over 0.5 mm radius for 10.000x. Furthermore, we show compatibility of the bottom barrier with the backplane process by fabricating AMOLED displays on GEN1-sized substrates.

Side leakage into the organic interlayer of unstructured hybrid thin-film encapsulation stacks and lifetime implications for roll-to-roll produced organic light-emitting diodes

Side leakage experiments have been performed on the organic interlayer, so-called organic coating for planarization (OCP), in a hybrid thin-film encapsulation (TFE) stack based on two silicon nitride (SiN) barrier layers that was developed for organic light-emitting diodes (OLED). To measure the side leakage into OCP, a metallic Ca thin-film...

High-temperature thin-film barriers for foldable AMOLED displays

We present a thin-film dual-layer bottom barrier on polyimide that is compatible with 350°C backplane processing for organic light-emitting diode displays and that can facilitate foldable active-matrix organic light-emitting diode devices with a bending radius of <2 mm. We demonstrate organic light-emitting diodes that survive bending over 0.5...

High-performance thin-film encapsulation for organic light-emitting diodes

Organic light-emitting diodes degrade rapidly by means of local cathode oxidation when exposed to the ambient atmosphere, resulting in visible non-emissive areas called black spots. High performance inorganic based encapsulations are required to protect the OLED. We have applied a hybrid thin-film encapsulation stack consisting of two inorganic...

Mechanistic study on black and grey spot growth in OLEDs performed on laser-ablated pinholes in the cathode

Local laser ablation of the cathode of OLEDs has been applied to create a population of pinholes of the same size. This enables the direct comparison at different conditions of black spots and grey spots in the emission of OLEDs as a result of water ingress into the device. We confirmed earlier observations on the operational effect of black...

Mechanism of the operational effect of black spot growth in OLEDs

When organic light-emitting diodes (OLEDs) are exposed to the ambient atmosphere, water penetration through pinholes in the cathode results in the formation of non-emissive areas (black spots) due to local oxidation of the cathode around the pinhole. This degradation effect severely limits the lifetime of OLED devices and requires high...

On the intrinsic moisture permeation rate of remote microwave plasma-deposited silicon nitride layers

We report on a low substrate temperature (110°C) remote microwave plasma-enhanced chemical vapor deposition (PECVD) process of silicon nitride barrier layers against moisture permeation for organic light emitting diodes (OLEDs) and other moisture sensitive devices such as organic photovoltaic cells (OPVs). Specifically, the influence of the SiH4...

Flexible barrier technology for enabling rollable AMOLED displays and upscaling flexible OLED lighting

The availability of a high performance thin-film barrier is the most critical challenge in upscaling and commercializing flexible OLED products. We report a flexible thin-film-barrier technology that meets lifetime specifications for OLED lighting, and demonstrate it in rollable QVGA a-IGZO AMOLED displays. Roll-to-roll manufacturing of this...

Thin-film barrier on foil for organic LED lamps

Within the Holst centre a transparent barrier on foil has been under development which is based on low-temperature plasma deposited silicon nitride films as intrinsic moisture barrier, stacked with planarization layers to spatially separate defects in these films. OLED lifetime testing and water vapor transmission rate measurements using a Ca...

High efficiency polymer LEDs: triplets and novel devices

We present results and a discussion of highly efficient polymer Light-Emitting Diodes (polymer LEDs, PLEDs). The external quantum efficiency in current standard devices reaches up to 2-4% only. We have explored two routes to enhance this value. In the first route, PEDOT/PSS is replaced with a novel anode or hole injection layer. The efficiency...