Screen-printed passive matrix displays and multicolor devices

Abstract

ABSTRACT Due to their outstanding properties organic light-emitting displays based on conjugated polymers are on the verge ofcommercialization. Two major disadvantages of the current processing technique for polymers, spin-coating of polymersolutions, are the material waste and the difficulties involved in patterning the polymers. Therefore we investigate thescreen-printing for the production of polymer displays. Here we present performance data of screen-printed light-emittingdiodes of different colors. In the production process of these diodes we printed two layers successively one over the other.Furthermore, we show images of printed multichrome demonstrators and passive matrix displays. Our data indicate that thescreen-printing technique has the potential to replace the “classical” spin-coat process. We observe luminance of10,000 cd/m² at 8 V and peak efficiencies exceeding 10 cd/A for green diodes and half lifetime of 170 hours at 80 °C and100 cd/m² for red diodes which corresponds to about 7,000 hours at room temperature. These values of printed devices arecomparable to those of spin-coated ones.Keywords: screen-printing, OLED, PLED, conjugated polymers, passive matrix display, multicolor