Skip to main content

3rd generation optical coatings for large area architectural glazing (3RD GENLAC)

Objective

Objectives and problems to be solved:
The field of large area deposition of energy efficient optical coatings has been subject to many innovations. Starting in the 80s, the first generation of large area coatings has been realized by magnetron sputtering or large area CVD of coatings with modest emissivity in the range of 10 … 16 % decreasing the U-value of double glazing units from 3 W/(m² K) to 1.3 … 1.6 W/(m²K). A second generation of energy efficient layers has been developed in the middle of the 90s in order to fulfil more stringent laws regarding energy consumption. These layers exhibit emissivity of 4 %. Applied as low E coating on DGUs, U-value of about U 1.1 W/(m²K) can be achieved. Further decrease of U-value to 0.5 W/(m²K) can be realized for low emissivity coated vacuum glazing. The established 2nd generation low E coatings cannot be applied on these glazing, unfortunately, due to their poor thermal stability. Using the first generation pyrolytic low E coatings, on the other hand, gives rise to heat resistant coatings, but the gain in U value is poor. Vacuum coatings based on pyrolytic low E coatings on position 2 and 3 exhibit U-value of U = 0.9 W/(m²K) and thus, there is considerable interest in high performance temperable low E coatings to decrease the U-value of vacuum glazing to approx. 1/3 of U-value obtained for conventional DGUs.
Description of the work:
The key technology necessary to achieve these goals is the technology of large area magnetron sputtering from ceramic targets. This allows for deposition of new materials such as complex ternary and quaternary spinell type layers, which cannot be deposited using conventional reactive processes. We will investigate into the material science and process technology for deposition of ultra durable spinell type layers, which are the key components for the deposition of temperable low E coatings.
The R&D work will be divided as follows:
· Developing ceramic target materials suited for DC sputtering of ultra durable dielectric layers to be used in insulator-metal-insulator interference stacks.
· Developing optimised process technologies for large area deposition of energy efficient coatings based on magnetron sputtering from ceramic targets.
· Developing new layer stacks for temperable low E coatings to reach U = 0.5 W/(m² K) and high performance low E sun control coatings to be applied on vacuum glazing and double glazing units.
· Transferring R&D results into pilot production.
Expected results and exploitation plans:
The main technical result will be a vacuum glazing which exhibits an U value of 0.5 W/(m²K) within a pilot production on large area substrates. The research on temperable high index materials will result in detailed knowledge on the properties of multi component oxide films to be used in architectural glazing. Due to the availability of U = 0.5 W/(m²K) technology, the green house effect can significantly be reduced. On the other hand, the research on multi component oxide layers can be exploited in other technological fields such as information display, photovoltaic and optoelectronics.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Address
54E,biedenroder Weg 54E
38108 Braunschweig
Germany

Participants (5)

APPLIED FILMS GMBH & CO. KG
Germany
Address
Siemensstrasse 100
63755 Alzenau
HERAEUS THIN FILM MATERIALS GMBH
Germany
Address
Wilhelm-rohn Strasse, 25
63450 Hanau
SEMCO GLASTECHNIK GMBH
Germany
Address
Feldmark 8
17034 Neubrandenburg
Scheuten Glasgroep BV
Netherlands
Address
Groethofstraat 21
5900 Venlo
UPPSALA UNIVERSITY
Sweden
Address
Regementsvagen 1
Uppsala