Martin Dinant Bijker

P‐111: A Thin Film Encapsulation Stack for PLED and OLED Displays

For a thin film (< 1 μm) encapsulation stack consisting of only 3 plasma deposited silicon nitride layers separated by a thin (< 100 nm) organic layer, a water permeation rate of below 10−5 g/m2 per day at 50 °C and 50% rH has been measured using the Ca test. PLED lifetimes of over 500 hours at 60 °C and 90% rH have been reached locally. While the Ca test indicates that pinhole free encapsulation is possible, edge and particle related defects still forecast a challenge for device encapsulation.

Good Surface Passivation of C-SI by High Rate Plasma Deposited Silicon Oxide

Silicon dioxide films were deposited by the (industrially applied) expanding thermal plasma technique using a gas mixture of argon-oxygen-octamethylcyclotetrasiloxane (OMCTS) and at deposition rates in the range of 5-23 nm/s. The films composition was investigated by means of spectroscopic ellipsometry, Fourier transform infrared spectroscopy and Rutherford backscattering. The composition was close to that of thermal oxide, with only a small residual hydrogen content of 2 at.%. The surface passivation of the silicon dioxide films was tested on 1.3Omegacm n-type FZ crystalline silicon wafers. A good level of surface passivation of 54 cm/s was reached after a 15 minute forming gas anneal at 600 degC

Controlling the silicon nitride film density for ultrahigh-rate deposition of top quality antireflection coatings

In this contribution we address the importance of a high mass density for silicon nitride films used as an antireflection coating on crystalline silicon solar cells. Two approaches for finding the optimized deposition conditions are presented. The outcome of these optimization studies clearly show that both the bulk and surface passivation benefit from a high mass density and that top quality antireflection coatings can be obtained at deposition rates up to 5 nm/s.

Ultra high-rate ETP deposited silicon nitride for >15% in-line processed multicrystalline silicon solar cells

The DEP/sub x/, developed by OTB Solar, uses the ETP technique for the deposition of a silicon nitride ARC on silicon solar cells. With this technique very high deposition rates can be achieved and experiments were carried out with Shell Solar to investigate the quality of these ultra high-rate deposited silicon nitride layers. An optimization study which focused on mass density and thermal stability showed that mc-Si solar cell efficiencies of >15% can be reached with silicon nitride grown at >5 nm/s.

Radiative wafer heating during plasma deposition process

Wafer heating with visible and infrared radiation is a well established method used in plasma deposition reactors used for solar cell production. A detailed study on radiative heat transfer as presented in this article gives a quantitative description by considering the spectral absorption of radiation in optical components, contamination of these components during plasma growth, the spectral emissivity of the silicon solar cell, and the effect of heat buffer components. Even with a clever implementation of heaters the net power incident on the wafer is shown to decrease to 60%. The wafer temperature ramp up time is shown to be dependent on the surface roughness and dopant level of the silicon solar cell, whereas the steady-state temperature during plasma growth is independent on these properties. Due to contamination during plasma growth, the wafer temperature decreases by 80K within one production shift, but this decrease can be minimized to 10–20K by implementing heat buffer components.

Infrared Heating with Opaque Quartz Reflector Technology

To ensure the performance of the OTB solar deposition tools, we utilize a novel opaque quartz reflector technology for our short-wave infrared lamps. The opaque quartz reflector has a superior industrial robustness over conventional reflector technologies. Angular intensity measurements show that the reflectance of the opaque quartz material can compete with that of a gold reflector. In the near future, further developed opaque quartz reflectors with a reflectance close to that of gold are foreseen

High-Quality Surface Passivation Obtained by High-Rate Deposited Silicon Nitride, Silicon Dioxide and Amorphous Silicon using the Versatile Expanding Thermal Plasma Technique

The expanding thermal plasma (ETP) is a novel plasma technique currently used by several solar cell manufacturers for the deposition of silicon nitride antireflection coatings on (multi-) crystalline silicon solar cells. In this paper we will show that the ETP technique is versatile and can be used for the deposition of silicon nitride, silicon dioxide and hydrogenated amorphous silicon with a good level of surface passivation. In this way the ETP technique can meet the future PV demands with respect to the decrease in wafer thickness and the use of n-type material that requires good electrical and optical quality thin films at both the front and the back side of the solar cell