Transparent conductive oxides TCO

Fraunhofer IST has been researching and developing transparent conductive oxides (TCO) for more than 10 years. Here the conductivity is produced in crystalline, transparent materials by adding a dopant. Examples of these materials: indium oxide (In2O3:Sn), zinc oxide (Z No:Al, ZnO:Ga, ZnO:Ti), tin oxide (SnO2:F, SnO2:Sb, SnO2:Ta) and most recently titanium oxide (TiO2:Nb). Efforts are focusing on optimizing the TCO material properties such as conductivity, light transmission and surface roughness, adaptation to customer-specific applications and the further development of the coating technology. Coatings such as transparent and conductive ITO films are also offered for research and development purposes.

What we offer

ITO coatings for the best performance

  • Substrate temperature TSub = 350°C
  • Specific resistance ρ = 157 µΩcm
  • Layer thickness e.g. 175 nm ⇒ Tvisual ≈ 87 %, layer resistance Rsh = 9 Ω

ITO coatings for sensitive substrates

  • Substrate temperature TSub = room temperature
  • Specific resistance ρ = 815 µΩcm
  • Layer thickness e.g. 148 nm ⇒ Tvisual ≈ 85.5 %, layer resistance Rsh = 55 Ω  

ITO coatings for coat and bend processes

  • Coating at room temperature with subsequent tempering
  • Specific resistance ρ ≈ 300 µΩcm
  • Layer thickness e.g. 140 nm ⇒ Tvisual = 86 %, layer resistance Rsh = 21 Ω
  • The substrate can be bent during the tempering process. The film does not tear (coat and bend process). The mechanical and chemical protection of the substrate is improved.
  • Coating complex components such as glass tubes is possible

Research and development work to adapt TCO for special applications such as structured TCOs (using photolithography or laser), heating coatings, switchable glass, flat screens (TFT), touch screens, low-emission coatings (low-e), heat reflective coatings, light emitting diodes (LED, OLED), solar cells, thin film transistors, thin glass, and architectural glass coatings.

Transmission of ITO layers on EagleXG glass, glass thickness: 1.1 mm.
© Fraunhofer IST
Transmission of ITO layers on EagleXG glass, glass thickness: 1.1 mm.