Specifics and Challenges to Flexible Organic Light-Emitting Devices

Abstract

Several recent developments in material science and deposition methods for flexible organic light-emitting devices (OLEDs) are surveyed. The commonly used plastic substrates are compared, according to their mechanical, optical, thermal, and chemical properties. Multilayer electrode structures, used as transparent electrodes, replacing conventional indium tin oxide (ITO) are presented and data about their conductivity, transparency, and bending ability are provided. Attention is paid to some of the most popular industrial processes for flexible OLEDs manufacturing, such as roll-to-roll printing, inkjet printing, and screen printing. Main specifics and challenges, related to the foils reliability, mechanical stability of the transparent electrodes, and deposition and patterning of organic emissive films, are discussed.

Controlling the Emission Spectrum of Binary Emitting Polymer Hybrids by a Systematic Doping Strategy via Förster Resonance Energy Transfer for White Emission

“…Organic-based materials for electronic applications, such as organic light-emitting diodes (OLEDs), have contributed significant advances in the field of polymer emitting devices. OLEDs gather several striking features, such as being low-cost; being easy to assemble by using wet methods; having a low power intake, owing to low conductivity of the organic materials; and having the ability to perform well in flat panel displays [1,2]. As white light is generally acquired by combining three principal colors (blue, green and red), two or more emitting constituents are piled in multilayer configuration [3][4][5][6] or assorted within a distinct layer by mixing or doping [7][8][9][10].…”

Thermochemical Modelling and Experimental Validation of In Situ Indium Volatilization by Released Halides during Pyrolysis of Smartphone Displays

“…Nevertheless, the organic polymer films, and especially the brominated flame retardants (BFR) enclosed in the polymer structure, play a fundamental role for this work, which is why their chemical composition is taken into account. Due to their high transparency and their good mechanical and electrical properties, polyethylene terephthalate (PET), polycarbonate (PC), polyethylene naphthalate (PEN) and polymethyl methacrylate (PMMA) are appropriate materials to be used in flat displays [7,8]. For the polarizer film, a polymer based on cellulose triacetate (CTA), is state of the art [9].…”

Printed Organic Light-Emitting Diodes on Fabric with Roll-to-Roll Sputtered ITO Anode and Poly(vinyl alcohol) Planarization Layer

“…Organic light-emitting diodes (OLEDs) are being developed to not only be flexible and foldable but also rollable for application in televisions, mobile phones, notebooks, automobiles, augmented reality, and virtual reality. OLEDs are suitable for such applications because of their desirable properties such as their high contrast, fast response, and being lightweight. − In particular, OLED-based electronics have advanced to wearable displays and as new forms of electronics integrated with biosensors, solar cells, healthcare devices, and even beauty products since the recent development and launch of foldable-type smartphones. , Additionally, dip-coating, , screen-printing, and inkjet printing − manufacturing methods, which are not limited to particular substrates, can be adopted for wearable electronics because of their large-area production at low manufacturing costs . For the electrodes for electronic textiles (e-textiles) application, the conductive materials of metals have been used (silver, copper, composite silver, and WO 3 ) via physical vapor deposition or printing methods via conductive polymers (poly­(3,4-ethylenedioxythiophene) polyaniline and polypyrrole) and carbon allotropes (graphene and carbon nanotubes) on textiles. − To manufacture a wearable electronic device that can be worn like clothing, e-textiles, fabricated by using woven fiber or fabric substrates, have been extensively investigated because of their advantages, such as their free-form design, portability, and applicability. − …”