47.3: Reliability of Transparent Conducting Substrates for Rollable Displays: A Cyclic Loading Investigation

Abstract

Failure mechanisms for flexible conducting substrates are investigated in the context of rollable/flexible display applications. Cyclic loading experiments (substrates subjected to multiple cycles of tensile strain) were carried out on both ITO coated PET and PEDOT:PSS coated PET substrates. The resistance was measured after each bending cycle. The resistance increased with number of cycles and was not reversible. Even if the tensile strain on the ITO/PET was below the virgin cracking threshold (∼2%) previously reported [APL 76, 1425 (2000)], slight increases in resistance were measurable after just a few cycles.

Engineered films for display technologies

“…To date there has been very little published work in this area and there is an important need to both define test protocols and determine how the structures behave on testing. Published work to date has focused on the behaviour of transparent conductive coatings on flexible substrates on flexing, 45,46 but this is outside the scope of this review.…”

Fabrication of Highly Conductive Poly(3,4‐ethylenedioxythiophene) Films by Vapor Phase Polymerization and Their Application in Efficient Organic Light‐Emitting Diodes

“…Attempts have also been made at implementing ITO in an emerging generation of flexible devices, but it is not an ideal choice owing to its inherent brittleness and susceptibility to conductivity changes after bending. [3][4][5] When this is considered alongside the ever-increasing cost of indium, it is clear that there is a pressing need to develop organic-based electrode materials for both flexible and rigid substrate devices. Here, we report the synthesis and optoelectronic properties of highly conductive (≤ 1180 S cm -1 ) poly(3,4-ethylenedioxythiophene) (PEDOT) films prepared by vapor phase polymerization (VPP).…”

P‐208: Flexible OLEDs with Anodes Formed by Vapour Phase Polymerization

“…This was followed by annealing in air at 80 °C for 2 min before the samples were transferred to a VPP chamber. The oxidant was based on a 0.45 μm filtered solution comprising isopropanol (IPA) with iron(III) tosylate Fe(OTs) 3 and pyridine in a weight ratio of 125:25:1. Small quantities of EDOT liquid were added to the chamber, which was subsequently sealed and placed under vacuum at ~10 mbar at room temperature (21 ºC).…”

“…Indium tin oxide (ITO) is the present industry standard transparent inorganic anode material for rigid devices, such as optical displays and solar cells, but it is not ideally suited to an emerging generation of flexible devices owing to its inherent brittleness and susceptibility to conductivity changes after bending. [2][3][4] When this is considered alongside the increasing cost of indium, it is clear that there is a pressing need to develop organic-based electrode materials.…”