Eliav Itzhak Haskal

Ink-jet printing of polymer light-emitting devices

Spin coating is a suitable technique for the fabrication of monochrome light-emitting polymer devices. For color displays, however, it is not the optimal solution when different polymers are applied. In principle, there are several technologies available for patterning light-emitting polymers. In this paper we discuss the advantages of drop-on-demand ink-jet printing over other printing methods. Special attention is given to some fundamental aspects of the printing process, such as drop formation and pixel filling. Examples of both monochrome and full color ink-jet printed passive matrix displays will be discussed.

21.1: Ink Jet Printing of Passive‐Matrix Polymer Light Emitting Displays

The requirement and characteristics for red, green and blue (RGB) electroluminescent polymers[1,2] suitable for fabricating monochrome and full-color passive-matrix polymer display[3] will be discussed. The controlled deposition of the light-emitting polymers is accomplished through the use of high-resolution ink jet printing[4,5], where the materials are first tested in devices prepared using spincoating techniques. The specifications for polymer materials, as well as the display design which must be taken into account to make a high-resolution passive-matrix display with low power consumption are presented.

Progress in polymer light-emitting devices at Philips

This paper will given an overview of the current state of the art of polymer light-emitting devices as they are manufactured at Philips. Electro-optical characterization as well as lifetime measurements will be discussed, with emphasis on the use of electroluminescent polymer materials and processes in monochrome graphic displays. The factors that determine power consumption on a system level will be detailed. Initial results on inkjet-printed devices will be shown.

Toward large-area roll-to-roll printed nanophotonic sensors

Polymers have become an important material group in fabricating discrete photonic components and integrated optical devices. This is due to their good properties: high optical transmittance, versatile processability at relative low temperatures and potential for low-cost production. Recently, nanoimprinting or nanoimprint lithography (NIL) has obtained a plenty of research interest. In NIL, a mould is pressed against a substrate coated with a moldable material. After deformation of the material, the mold is separated and a replica of the mold is formed. Compared with conventional lithographic methods, imprinting is simple to carry out, requires less-complicated equipment and can provide high-resolution with high throughput. Nanoimprint lithography has shown potential to become a method for low-cost and high-throughput fabrication of nanostructures. We show the development process of nano-structured, large-area multi-parameter sensors using Photonic Crystal (PC) and Surface Enhanced Raman Scattering (SERS) methodologies for environmental and pharmaceutical applications. We address these challenges by developing roll-to-roll (R2R) UV-nanoimprint fabrication methods. Our development steps are the following: Firstly, the proof of concept structures are fabricated by the use of wafer-level processes in Si-based materials. Secondly, the master molds of successful designs are fabricated, and they are used to transfer the nanophotonic structures into polymer materials using sheet-level UV-nanoimprinting. Thirdly, the sheet-level nanoimprinting processes are transferred to roll-to-roll fabrication. In order to enhance roll-to-roll manufacturing capabilities, silicone-based polymer material development was carried out. In the different development phases, Photonic Crystal and SERS sensor structures with increasing complexities were fabricated using polymer materials in order to enhance sheet-level and roll-to-roll manufacturing processes. In addition, chemical and molecular imprint (MIP) functionalization methods were applied in the sensor demonstrators. In this paper, the process flow in fabricating large-area nanophotonic structures by the use of sheet-level and roll-to-roll UV- nanoimprinting is reported.

Simulation and realization of a 4-inch diagonal monochrome passive-matrix polymer QVGA display

To explore the practical size limits of passive-matrix polymer light emitting displays, a 4-inch diagonal monochrome QVGA display was simulated, fabricated and tested. To design this display, a simulation program was developed which takes into account the multiplex rate, aperture ratio of the pixels, parasitic capacitance in the display, series resistance of the anodes and cathodes, and the decrease in efficiency at higher applied voltages. The effects of these parameters on the power consumption will be addressed. In addition, technological aspects of introducing a shunt metal in the pixels will be presented. Finally, the measurements of the fabricated display are compared to the simulation and discussed.