Method for applying a thin film barrier stack to a device with microstructures, and device provided with such a thin film barrier stack

A method for applying a thin film barrier stack to a device with microstructures, such as, for instance, an OLED, wherein the thin film barrier stack forms a barrier to at least moisture and oxygen, wherein the stack is built up from a combination of org. and inorg. layers, characterized in that a first org. intermediate layer is applied, wherein the org. intermediate layer is applied in liq. form, wherein the viscosity of the org. intermediate layer liq. is so low that grooves, hollows and like narrow cavities are at least partly filled up with the org. liq. under the influence of capillary forces while other parts of the device are only covered with a thin layer of the org. liq., such that a layer of variable thickness is formed

Bulk passivation of multicrystalline silicon solar cells induced by high-rate-deposited (>1 nm/s) silicon nitride films

Silicon nitride (a-SiNx:H) films deposited by the expanding thermal plasma at high rate (> 1 nm/s) have been studied for application as anti-reflection coatings for multicrystalline silicon (mc-Si) solar cells. Internal quantum efficiency measurements have revealed that bulk passivation is achieved after a firing-through process of the a-SiNx:H as deposited from NH3/SiH4 and N2/SiH4 plasmas. However, the a-SiNx:H films deposited from N2/SiH4 show a lower passivation quality than those deposited from NH3/SiH4. This has been attributed to a poorer thermal stability of the films deposited from the N2/SiH4 plasma, resulting in structural changes within the film during the firing step

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/NH3 gas flow ratio on the layer composition and intrinsic moisture barrier performance is investigated, as inferred from Fourier Transform Infrared (FTIR) spectroscopy, Rutherford Back Scattering (RBS) analysis, and the calcium test. Since the presence of extrinsic factors for barrier failure such as pinholes and contamination particles (defects) is largely determined by the substrate conditioning and environment, the focus in this research is on the intrinsic permeability of the silicon nitride films, as measured by monitoring the homogeneous degradation of defect (e.g. pinholes and contamination particles)-free calcium regions. The investigated films have tunable chemical composition and optical properties and moderate residual strain levels varying from tensile to compressive. Despite this variation in film properties, the intrinsic water vapor transmission rate (WVTR) is found to be constant at a level of 1 · 10- 5 g/m2 day at 20 °C/50%RH conditions for films deposited at 0.1–0.5 nm/s. When the total gas flow rate is increased in order to achieve higher growth rate processing (0.2–1.0 nm/s), a higher permeability is measured at increased SiH4/NH3 ratio. The development of high surface roughness in the silicon nitride layer, as shown by AFM analysis, suggests cluster/dust formation in the plasma and powder inclusion during film deposition. This eventually leads to higher water vapor transmission rate of the deposited layers