New method

Ultra-Low Oxygen Transmission Rate Measurement

JOANNEUM RESEARCH offers a superior alternative to established methods for measuring oxygen transmission rates of flexible ultra-barrier encapsulation materials in organic electronics.

The development of flexible and cheap electronic devices such as organic photovoltaic cells is achieving continuous successes and steering towards the conquest of a wide field of applications. Components made of organic semiconductors are cheap in their production because the active substances can be applied and structured by simple processes like inkjet printing. Furthermore, they are mechanically flexible. However, one of the major drawbacks of the technology is the extraordinary sensitivity to oxygen and water vapour. The omnipresent atmospheric gases cause the immediate degradation of the sensitive substances and thus destroy the device. In consequence, organo-electronics require being encapsulated using absolutely airtight materials. Barriers with oxygen transmission rates (“OTR”) as low as 10-5 cm3 m-2 day-1 bar-1 and water vapour transmission rates (“WVTR”) of 10-5 g m-2 day-1 are required for sufficient operation time and shelf-life, permitting the technical application of organo-electronic devices in the first place. Even the best analytical instruments on the market have limits of detection, which are lagging behind the demands by orders of magnitude and thus are unsuitable for the characterization of such ultra-barriers.

Character-istics

JOANNEUM RESEARCH offers a superior method based on the unique properties of opto-chemical sensors, above all the capability of consumption-less detection and extraordinary sensitivity. The luminescent response to modulated light, which is altered in the presence of oxygen, is recorded by an opto-electronic instrument in a non-invasive manner. The unit achieves a limit of detection in the 10-5cm3 m-2 day-1 bar-1 regime. It is therefore among the most sensitive O2 permeability testers, outperforming commercial instruments by two orders of magnitude.

FEATURES

  • measurement range (OTR): 1*10-5 bis 50 cm3 m-2 day-1 bar-1
  • sample: smooth film, diameter 40 – 45 mm
  • thickness: < 1 mm
  • measurement time: several hours to days, depending on the permeability of the barrier layer

CUSTOMERS AND COOPERATION PARTNERS INCLUDE

  • Graz University of Technology (ICTM)
  • Fraunhofer-Institute for Process Engineering and Packaging (IVV)
  • Fraunhofer-Institute for Silicate Research (ISC)
  • Konarka
  • Systech Instruments
  • Isovolta AG
  • Greiner Packaging GmbH
  • University of Bayreuth
  • Polymer Competence Center Leoben GmbH
  • OMV Exploration & Production GmbH

The Sensor Systems research group has comprehensive experience in developing chemical and biosensor components, integrating them into complex sensor systems and translating the innovations developed into commercial products together with industrial partners. This includes the development of active sensor layers and associated surface modification and coating methods, microfluidic systems, sensor optics, excitation and processing electronics as well as permeability testing setups for more complex permeants such as aromatic hydrocarbons.