Transparent electrodes are key components in almost every optoelectronic device. Light can pass through and the electrodes can provide a current or electric field to control and change the optical properties of the devices.
Optically transparent electrodes are used in wide range of applications such as in solar cells, touch screens, light emitting diodes and flexible displays. Optical propertis of devices can be controlled and changed. CleviosTM supports in the development of new generations optoelectronic devices by combining high performance and novel functionality transparent conductive electrodes that are flexibile, bendable and adaptable.
Clevios™ for transparent conductive electrodes
Prominent examples such as LCD, e-writing boards, or PDLC smart windows are based on liquid crystal molecules. Clevios™ can be used in all these devices.
Clevios™ is the flexible and reliable conductive material for transparent conductive electrodes.
Clevios™ offers the following benefits:
- Economical coating processes and affordable costs
- Selective electrode patterning by direct printing (inkjet, slot-die, gravure)
- Precise control of sheet resistance over a broad range from 150 Ohm/sq to several kOhm/sq
- Extended sheet resistance range of 15 – 150 Ohm/sq with Clevios™ HY E hybrid materials
- Low light reflection due to a low refractive index similar to plastic or glass
- Outstanding mechanical flexibility
- Stretchable and thermoforming properties are possible
- High transmission and low haze
A product family
Clevios™ PH 1000 is the highest conductive aqueous PEDOT:PSS dispersion and raw material for coating formulations and printing inks. Clevios™ F ET is a ready-to-use coating formulation for slot-die and other roll-to-roll methods (Figure 1). Printing inks are available for screen-printing, Clevios™ S Series, and inkjet printing, Clevios™ P Jet products.
Clevios™ HY E is a hybrid material of silver nanowires and PEDOT:PSS and extends the sheet resistance range to as low as 15 Ohm/sq.
All conductive coatings can be patterned and structured by laser or by a wet-chemical process with Clevios™ Etch.
PDLC for Changing Transparency
Liquid crystals such as PDLCs (polymer dispersed liquid crystals) are used in smart windows that can change from clear transparent to milky translucent in the blink of an eye when an electric field is applied by the Clevios™ electrode films that sandwich the PDLC (Figure 2).
A similar technology is used in writing boards where pressure from a stylus makes writing or drawing visible and erasable with the push of a button that applies an electric field to reorient the liquid crystal molecules.
Clevios™ in LCD and e-paper displays
Excellent optical properties and high conductivities make Clevios™ a strong candidate for transparent electrodes also in LCD and e-paper displays (Figure 3). This offers opportunities to implement low-cost manufacturing steps in the display manufacturing processes.