Abstract
Description
Although it is possible to print many different kinds of electronic displays,
in order for them to be commercially successful, they must be robust enough to
survive for the necessary time and conditions required of the display. This
condition has been a limitation of many printable electronic displays. Beyond
printability and functionality, one of the most important requirements is
encapsulation. Many of the materials used in printed electronic displays are
chemically sensitive, and will react with many environmental components.
This concise and highly targeted report from IDTechEx technology analyst Dr
Harry Zervos gives an in-depth review of the issues, as well as forecasts for
OLEDs and OPV, in order to understand the influence that the development of
flexible barriers will have on the mass deployment and adoption of flexible
electronics and photovoltaics.
A large opportunity lies in the development of devices in a flexible form
factor, allowing them to be more robust, lightweight and versatile in their
use.
However, many of the materials used in OLED displays and organic photovoltaics
are sensitive to the environment, limiting their lifetime. These materials can
be protected using substrates and barriers such as glass and metal, but this
results in a rigid device and does not satisfy the applications demanding
flexible devices. Plastic substrates and transparent flexible encapsulation
barriers can be used, but these offer little protection to oxygen and water,
resulting in the devices rapidly degrading.
In order to achieve device lifetimes of tens of thousands of hours, water
vapor transmission rates (WVTR) must be 10-6 g/m2/day, and oxygen transmission
rates (OTR) must be < 10-3 cm3/m2/day. For Organic Photovoltaics, the
required WVTR is not as stringent as OLEDs require but is still very high at a
level of 10-5 g/m2/day. These transmission rates are several orders of
magnitude smaller than what is possible using any plastic substrate, and they
can also be several orders of magnitude smaller than what can be measured
using common equipment designed for this purpose. For these (and other)
reasons, there has been intense interest in developing transparent barrier
materials with much lower permeabilities.
This concise and unique report from IDTechEx gives an in-depth review of the
needs, emerging solutions and players.
It addresses specific topics such as:
- Companies which are active in the development of high barrier films and
their achievements on the field to date.
- Surface smoothness and defects (such as cracks and pinholes) and the
effect that these characteristics would have on the barrier behavior of the
materials studied.
- Traditional methods of measurement of permeability are reaching the end of
their abilities. The MOCON WVTR measurement device, which has been an industry
standard, cannot give adequate measurements at the low levels of permeability
required for Organic Photovoltaics and OLEDs. Other methods of measurement and
equipment developed are being discussed.
- Forecasts for OLEDs and OPV, in order to understand the influence that the
development of flexible barriers would have at the mass deployment and
adoption of these technologies.
For those developing flexible electronics, seeking materials needs and
opportunities, this is a must-read report.
Report Statistics
- Pages: 112
- Tables: 10
- Figures: 42
- Last update: April 2010
Table of Contents
1. SCOPE
2. INTRODUCTION TO ENCAPSULATION
3. SURFACE SMOOTHNESS - DEFECTS
- 3.1. Important considerations of surface smoothness
- 3.2. Micro Defects
- 3.2.2. Pinholes
- 3.2.3. Smoothness / Cracks-Scratches
- 3.2.4. Nanodefects
4. COMPANIES
- 4.1. Vitex
- 4.2. GE
- 4.3. 3M
- 4.4. CPI
- 4.5. Fraunhofer -POLO Alliance
- 4.6. Alcan Packaging
- 4.7. Other technologies - High barrier adhesives
- 4.8. Best performing barriers developed to date
5. BARRIER MEASUREMENTS
- 5.1. The Calcium test
- 5.2. MOCON
- 5.3. Illinois Instruments
- 5.4. Fluorescent Tracers
- 5.5. Black Spot Analysis
- 5.6. Tritium Test
- 5.7. CEA
- 5.8. 3M
- 5.9. IMRE
- 5.10. Mass Spectrocopy - gas permeation (WVTR & OTR potential applications)
- 5.11. Standardization efforts
6. FORECASTS FOR BARRIER FILMS FOR FLEXIBLE ELECTRONICS 2010-2020
- 6.1. The potential significance of organic and printed inorganic
electronics
- 6.2. Forecasts for flexible electronics 2010-2020
- 6.3. Barrier films market size
7. CONCLUSIONS
8. REFERENCES
APPENDIX 1: ATOMIC LAYER DEPOSITION
APPENDIX 2: GLOSSARY
APPENDIX 3: IDTECHEX PUBLICATIONS AND CONSULTANCY
TABLES
- 2.1. Water vapor and oxygen transmission rates of various materials
- 2.2. Requirements of barrier materials
- 3.1. Oxygen transmission rates of polypropylene with various
coatings. 4, 7
- 4.1. Overview of promising high barrier technologies
- 5.1. Lower detection limits of several barrier performance
measurement techniques
- 5.2. Metrics and standards for organic solar cell components42
- 6.1. Leading market drivers 2020
- 6.2. Market value (US$ billion) of flexible/conformal electronics
2010-2020
- 6.3. Total market value of flexible vs. rigid electronics 2010-2020
- 6.4. Barrier Layer Market Forecasts 2010-2020
FIGURES
- 1.1. Examples of flexible OLED displays by SONY and AddVision
- 1.2. Flexible OLED fabricated using IMRE' s high barrier substrate
and encapsulation technique44
- 1.3. Flexible Solar Cell developed by Fraunhofer IPMS
- 2.1. Schematic diagrams for encapsulated structures a) conventional
b) laminated c) deposited in situ4
- 2.2. Scanning electron micrograph image of a barrier film cross
section6
- 3.1. Visual defects of a selection of materials with barrier films
highlighted through calcium corrosion test. Optical microscope magnification
10x. 44
- 3.2. SEM pictures of the Atmospheric Plasma Glow Discharge
deposited silica-like films on polymer substrates. Left: Film with embedded
dust particles . Right: uniform film27
- 3.3. OTR as a function of defect density, the correlation between
defect density and the oxygen transmission rate
- 3.4. SEM image of a pinhole defect formed from a dust particle32
- 3.5. Scanning electron microscope image of ITO coated on
parylene/polymer film34
- 3.6. The measurement of OLED' s lifetime of SiON/PC/ITO and
SiON/parylene/PC/parylene/ITO substrate34
- 4.1. Examples of polymer multi-layer (PML) surface planarization a)
OLED cathode separator structure b) high aspect ratio test structure. 3, 8
- 4.2. Vitex multilayer deposition process8
- 4.3. SEM cross section of Vitex Barix material with four dyads
- 4.4. Optical transmission of Vitex Barix coating8
- 4.5. Edge seal barrier formation by deposition through shadow
masks10
- 4.6. Three dimensional barrier structure.Polymer is shown in red,
and oxide (barrier) shown in blue10
- 4.7. Schematic of flexible OLED with hybrid encapsulation31
- 4.8. Schematic of cross section of graded barrier coating and
complete barrier film structure1
- 4.9. DuPont Displays technology pipeline
- 4.10. Scanning electron micrograph of a thin hybrid polymer coating
on SiOx deposited on a flexible PET film 46
- 4.11. OTR values achieved with different POLO multilayers46
- 4.12. ALCAN Packaging flexible barrier based on PET and SiOx47
- 4.13. Area sealing55
- 4.14. DELO' s light curing adhesive solution for electrophoretic
displays55
- 4.15. Performance characteristics of DELO' s light-curing materials55
- 4.16. Specifications on WVTR for different applications, as seen by
Vitex Systems36
- 4.17. 3M specifications on WVTR and OTR for high barrier
applications with stringent requirements 14
- 5.1. 2.25 mm2 area of a 50 nm layer of Ca deposited onto barrier
coated PET viewed through the substrate. i.Image after 1632 h of
exposure to atmosphere; ii.Image analysis whereby the grey scale of Ca
degradation is processed to yiel
- 5.2. A simple set-up for measuring optical transmission of calcium
test cells48
- 5.3. MOCON' s Aquatran™ Model 138
- 5.4. MOCON' s Aquatran™ schematic38
- 5.5. MOCON' s OX-TRAN® Model 2/1039
- 5.6. Silica induced black spots, letters A & B mark black spots
with a centralized black dot (silica particle)32
- 5.7. Black spot formation and growth mechanisms 32
- 5.8. General Atomics HTO WVTR testing apparatus40
- 6.1. Market value (US$ billion) of flexible/conformal electronics
2010-2020
- 6.2. Total market value of flexible vs. rigid electronics 2010-2020
- 6.3. Barrier Layer Market Forecasts 2010-2020
- 6.4. Size of opportunity
- 7.1. The iRex iLiad and the Amazon Kindle rigid e-book readers
- 7.2. PVI' s flexible electrophoretic display and color
electrophoretic display by SAMSUNG LCD, demonstrated at SID 2008
