OTFT Backplanes: Printed Charge Injection Layers

Organic thin film transistor (OTFT) device technology could revolutionize display manufacturing by printing TFT backplanes and further improving the flexibility of displays in future. Clevios™ inkjet grades with tunable workfunctions and conductivities are prime candidates for this new display generation.

OTFT Backplanes: Printed Charge Injection Layers

Thin Film Transistor (TFT) backplanes of LCD and OLED displays are manufactured in complex processes that include repeated vacuum sputtering and photolithographic patterning steps using expensive masks.

In principle, it is possible to print thin film transistors using organic materials. Organic semiconductors have improved significantly with respect to their charge carrier mobilities and surpass amorphous silicon by far.

Home printing of displays using an inkjet printer is currently not possible, but with ongoing development this might become feasible in the near future for simple displays or sensors. Flexibility of the display backplanes is another consideration and driver of printed organic TFT technology.

Clevios™ as transistor electrodes and printed by inkjet

Clevios™ PEDOT:PSS can be used as transistor electrodes and printed by inkjet. Special Clevios™ HIL materials with tuned work functions can further improve the charge injection properties of metal electrodes and thus optimize transistor performance.

The principle of inkjet printing Clevios™ as source, drain, and gate electrode in an organic transistor has long been demonstrated in scientific publications Halik et al. Appl. Phys. Lett. 81, 289 (2002).

to top