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Electrochromic polymer systems

Electrochromic (EC) materials are known to change their optical properties/colour when an electrical voltage is applied. The term "EC module" refers to an electrochemical cell with which an electrochromic effect in solid film materials can be made technologically usable.

Applications

  • Information displays
  • Light filters for cameras
  • Sunglasses, visors
  • Building glazing
  • privacy screens, sunshades
  • transparent interior walls

The activities of the TITK (since 2007) in the field of EC modules include:

  • Synthesis and electro-optical characterisation of electrochromic polymers.
  • Development of ion storage layers (e.g. TiO2-CeO2), complementary EC polymers
  • Development of solid electrolytes based on ionic liquids
  • Manufacturing technologies for EC modules

Priorities and results achieved:

  • Coating processes of EC polymer, ion storage layer and electrolyte systems (spin coating, doctor blade technology, ink jet printing, spray, RzR).
  • Up-scaling of the individual components of the EC modules and manufacturing technologies on glass and flexible substrates (previously 400 cm2)
  • flexible curved transparent EC modules
  • UV resistance and long-term stability of the EC effect in a wide temperature range (long-term stability at RT: >10,000 cycles, EC contrast Δ%T: >50 (colourless / blue), EC efficiency (η): 300-800 cm2/C)
  • Switching speed between two colour states 5 to 30 sec
  • Wide colour range of EC modules (colourless / orange / blue, colourless / blue, yellow / brown / greyish blue, wine red / greyish purple / blue, wine red / dark purple
Electrochromic effect demonstrated on an encapsulated EC module with EC polymer in the neutral state (colourless) and oxidised blue and oxidised orange forms, EC area: approx. 97 cm2
Electrochromic effect demonstrated on an encapsulated EC module with EC polymer in the neutral state (colourless) and oxidised blue and oxidised orange forms, EC area: approx. 97 cm2