An attractive approach to full color OLED displays is based on white emitting copolymers and color filters. In this paper the special impact of broadband emitting copolymers based on polyspirobifluorene structures is discussed. The EL spectra of broadband emitters in PLEDs are strongly influenced by interference effects as well as by the driving conditions. Experimental results could be confirmed by modelling. Adjustment of emission spectra to the color filter characteristics lead to improved efficiency.

By using the well-known Hantzsch method and starting from some mono- and bifunctional aryl-substituted thioureas, thioacetamides, and bromoketones several new aryl-substituted 2-aminothiazoles and 2-aminothiophenes have been prepared and tested as hole transport materials for OLEDs.

Due to their outstanding properties organic light-emitting displays based on conjugated polymers are on the verge of commercialization. Two major disadvantages of the current processing technique for polymers, spin-coating of polymer solutions, are the material waste and the difficulties involved in patterning the polymers. Therefore we investigate the screen-printing for the production of polymer displays. Here we present performance data of screen-printed light-emitting diodes 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 the screen-printing technique has the potential to replace the "classical" spin-coat process. We observe luminance of 10,000 cd/m(2) at 8 V and peak efficiencies exceeding 10 cd/A for green diodes and half lifetime of 170 hours at 80 degreesC and 100 cd/m(2) for red diodes which corresponds to about 7,000 hours at room temperature. These values of printed devices are comparable to those of spin-coated ones.

AbstractWe present investigations on a new red emitting dye RedATDB. Doping small concentrations of RedATDB in an Alq3 host leads to red OLEDs (x=0.650, y=0.346) with good efficiency values (4.3 cd/A; 2.1 lm/W @ 100 cd/m2). To test our material for display applications, we produced monochrome red passive matrix displays (32 × 100 pixels). With appropriate display measurement equipment we investigate the pixel resolved electrical (I‐V) and optical (luminance) characteristics. Homogenous pixel performance data in terms of luminance and driving voltage has been observed.

Due to their outstanding properties, e.g., good contrast, wide viewing angle, low power consumption, and self-emission organic light-emitting (OLE) displays on the basis of conjugated polymers are on the verge of commercialization. Two major disadvantages of the current processing technique for the polymers—spin coating—are the material waste and the difficulties involved in patterning multichrome or even full-color displays. Therefore, we investigated the screen-printing technique for the production of OLE displays. In this letter, we present performance data and images of screen-printed OLE diodes. They are already comparable to spin-coated ones. We observed luminance of 10 000 cd/m2 at 8 V and peak efficiencies exceeding 10 cd/A for green diodes. These data indicate that printed organic displays have the potential to replace “classical” spin-coated devices.