29-12-2012, 06:41 PM
Organic LED Displays (OLEDs) - The Next Trend?
[attachment=45887]
Advantages of Plastic Electronics
One big advantage of plastic electronics is that there is virtually no restriction on size. Conventional
semiconductor components have become smaller and smaller over the course of time. Silicon is the base
material of all microelectronics and is eminently suited for this purpose. However, the making of larger
components is difficult and therefore costly. The silicon in semiconductor components has to be mono
crystalline: it has to have a very pure crystal form without defects in the crystal structure. This is achieved by
allowing melted silicon to crystallize under precisely controlled conditions. The larger the crystal, the more
problematic this process is. Plastic does not have any of these problems, so that semi-conducting plastics are
paving the way for larger semiconductor components.
With the increasing popularity of LCD screens to replace the conventional picture (cathode ray) tube,
PolyLED should emerge as another suitable candidate. A screen based on PolyLEDs has obvious advantages:
the screen is lightweight and flexible, so that it can be rolled up. With plastic chips you can ensure that the
electronics driving the screen are integrated in the screen itself. Other applications of the PolyLED are
luminous information screens of almost unlimited size, for example alongside motorways or at train stations.
Philips and PolyLed
Since the discovery of polymer-based light emitting diode (LED) in 1989, Philips has been working on
PolyLED. Today, Philips is the first to ship monochrome PolyLED displays in mass production. Philips
Research is now concentrating on the development of PolyLED technologies for next-generation full-color
displays and on ways of integrating PolyLEDs into flexible displays.
State-of-the-art
Launched in September 2002, the Sensotec Philishave is the first ever product equipped with a display based
on superior PolyLED technology and is prominently featured in the latest James Bond movie, Die Another
Day.
In 2002, SANYO, Kodak, and SKD shipped 300 OLED displays for trial use in mobile phones. In order to
increase production of low temperature poly-silicon TFT LCD displays, the demand for which currently
exceeds capacity and in order to establish a mass production infrastructure required for full scale mass
production startup of OLED displays, a factory of Tottori SANYO Co., Ltd. was placed under the control of
SANYO LCD Engineering Co., Ltd. in February of 2003. The manufacturing line used for the production of
amorphous silicon TFT displays is was shifted over to the production of low temperature poly-silicon TFT
displays. Production of Low temperature poly-silicon TFT displays on the converted line began in April of
2003.
Some of the challenges OLEDs have to face:
* Entering a market already dominated by a large CRT-to-LCD panel conversion process
* Breaking into the consumer mindset where viewers are still struggling to understand new technologies
* Ensuring competitive refresh rates, contrast ratios, black levels and overall performance
* Quickly meeting and exceeding price points set by current LCD/plasma technology leaders
While the last issue may be quickly resolved due the nature of the OLED manufacturing process itself, the
first three items have yet to be proven and undertaken. OLED technology has to go from novelty to practical
competitor in a market that is constantly evolving to exceed and extend beyond its current boundaries. LCD
screens are getting faster and faster, while Plasma displays continue to drop in price and go up in performance
(check out some of the latest "real-world" contrast ratios achieved by Pioneer and other manufacturers - they
rival or exceed that of many high-end direct view CRTs and RPTVs).
Organic light-emitting diode
An organic light-emitting diode (OLED), also Light Emitting
Polymer (LEP) and Organic Electro-Luminescence (OEL), is
any light-emitting diode (LED) whose emissive
electroluminescent layer is composed of a film of organic
compounds. The layer usually contains a polymer substance
that allows suitable organic compounds to be deposited. They
are deposited in rows and columns onto a flat carrier by a
simple "printing" process. The resulting matrix of pixels can
emit light of different colors.
Such systems can be used in television screens, computer
displays, portable system screens, advertising, information and
indication. OLEDs can also be used in light sources for
general space illumination, and large-area light-emitting
elements. OLEDs typically emit less light per area than
inorganic solid-state based LEDs which are usually designed for use as point-light sources.
A significant benefit of OLED displays over traditional liquid crystal displays (LCDs) is that OLEDs do not
require a backlight to function. Thus they draw far less power and, when powered from a battery, can operate
longer on the same charge. Because there is no need to distribute the backlight, an OLED display can also be
much thinner than an LCD panel. OLED-based display devices also can be more effectively manufactured
than LCDs and plasma displays. But degradation of OLED materials has limited the use of these materials.[1]
History
Bernanose and co-workers first produced electroluminescence in organic materials in the early 1950s by
applying a high-voltage alternating current (AC) field to crystalline thin films of acridine orange and
quinacrine. In 1960, researchers at Dow Chemical developed AC-driven electroluminescent cells using doped
anthracene.
The low electrical conductivity of such materials limited light output until more conductive organic materials
became available, especially the polyacetylene, polypyrrole, and polyaniline "Blacks". In a 1963 series of
papers, Weiss et al. first reported high conductivity in iodine-doped oxidized polypyrrole. They achieved a
conductivity of 1 S/cm. Unfortunately, this discovery was "lost"[clarify], as was a 1974 report of a melaninbased
bistable switch with a high conductivity "ON" state. This material emitted a flash of light when it
switched.
In a subsequent 1977 paper, Hideki Shirakawa et al. reported high conductivity in similarly oxidized and
iodine-doped polyacetylene. Alan J. Heeger, Alan G. MacDiarmid & Hideki Shirakawa received the 2000
Nobel Prize in Chemistry for "The discovery and development of conductive organic polymers". The Nobel
citation made no reference to the earlier discoveries.
Other companies
The Optimus Maximus keyboard currently in development by the Art. Lebedev Studio is expected to use 113
48×48-pixel OLEDs (10.1×10.1 mm) for its keys.
OLEDs can be used in High-Resolution Holography (Volumetric display). Professor Orbit showed on May
12, 2007, EXPO Lisbon the potential application of these materials to reproduce three-dimensional
video.[citation needed]
OLEDs could also be used as solid-state light sources. OLED efficacies and lifetime already exceed those of
incandescent light bulbs, and OLEDs are investigated worldwide as source for general illumination; an
example is the EU OLLA project.[36]
On March 11, 2008 GE Global Research demonstrated the first successful roll-to-roll manufactured OLED,
marking a major milestone towards cost effective production of commercial OLED technology. The 4 year,
$13 million research project was carried out by GE Global Research, Energy Conversion Devices, Inc and the
U.S. Commerce Department’s National Institute of Standards and Technology (NIST).
Commercial uses
OLED technology is used in commercial applications such as small screens for mobile phones and portable
digital audio players (MP3 players), car radios, digital cameras, and high-resolution microdisplays for headmounted
displays. Such portable applications favor the high light output of OLEDs for readability in sunlight,
and their low power drain. Portable displays are also used intermittently, so the lower lifespan of OLEDs is
less important here. Prototypes have been made of flexible and rollable displays which use OLED's unique
characteristics. OLEDs have been used in most Motorola and Samsung color cell phones, as well as some
Sony Ericsson phones, notably the Z610i, and some models of the Sony Walkman. It is also found in the
Creative Zen V/V Plus series of MP3 players. Nokia has also introduced recently some OLED products,
including the 7900 Prism and Nokia 8800 Arte.
[attachment=45887]
Advantages of Plastic Electronics
One big advantage of plastic electronics is that there is virtually no restriction on size. Conventional
semiconductor components have become smaller and smaller over the course of time. Silicon is the base
material of all microelectronics and is eminently suited for this purpose. However, the making of larger
components is difficult and therefore costly. The silicon in semiconductor components has to be mono
crystalline: it has to have a very pure crystal form without defects in the crystal structure. This is achieved by
allowing melted silicon to crystallize under precisely controlled conditions. The larger the crystal, the more
problematic this process is. Plastic does not have any of these problems, so that semi-conducting plastics are
paving the way for larger semiconductor components.
With the increasing popularity of LCD screens to replace the conventional picture (cathode ray) tube,
PolyLED should emerge as another suitable candidate. A screen based on PolyLEDs has obvious advantages:
the screen is lightweight and flexible, so that it can be rolled up. With plastic chips you can ensure that the
electronics driving the screen are integrated in the screen itself. Other applications of the PolyLED are
luminous information screens of almost unlimited size, for example alongside motorways or at train stations.
Philips and PolyLed
Since the discovery of polymer-based light emitting diode (LED) in 1989, Philips has been working on
PolyLED. Today, Philips is the first to ship monochrome PolyLED displays in mass production. Philips
Research is now concentrating on the development of PolyLED technologies for next-generation full-color
displays and on ways of integrating PolyLEDs into flexible displays.
State-of-the-art
Launched in September 2002, the Sensotec Philishave is the first ever product equipped with a display based
on superior PolyLED technology and is prominently featured in the latest James Bond movie, Die Another
Day.
In 2002, SANYO, Kodak, and SKD shipped 300 OLED displays for trial use in mobile phones. In order to
increase production of low temperature poly-silicon TFT LCD displays, the demand for which currently
exceeds capacity and in order to establish a mass production infrastructure required for full scale mass
production startup of OLED displays, a factory of Tottori SANYO Co., Ltd. was placed under the control of
SANYO LCD Engineering Co., Ltd. in February of 2003. The manufacturing line used for the production of
amorphous silicon TFT displays is was shifted over to the production of low temperature poly-silicon TFT
displays. Production of Low temperature poly-silicon TFT displays on the converted line began in April of
2003.
Some of the challenges OLEDs have to face:
* Entering a market already dominated by a large CRT-to-LCD panel conversion process
* Breaking into the consumer mindset where viewers are still struggling to understand new technologies
* Ensuring competitive refresh rates, contrast ratios, black levels and overall performance
* Quickly meeting and exceeding price points set by current LCD/plasma technology leaders
While the last issue may be quickly resolved due the nature of the OLED manufacturing process itself, the
first three items have yet to be proven and undertaken. OLED technology has to go from novelty to practical
competitor in a market that is constantly evolving to exceed and extend beyond its current boundaries. LCD
screens are getting faster and faster, while Plasma displays continue to drop in price and go up in performance
(check out some of the latest "real-world" contrast ratios achieved by Pioneer and other manufacturers - they
rival or exceed that of many high-end direct view CRTs and RPTVs).
Organic light-emitting diode
An organic light-emitting diode (OLED), also Light Emitting
Polymer (LEP) and Organic Electro-Luminescence (OEL), is
any light-emitting diode (LED) whose emissive
electroluminescent layer is composed of a film of organic
compounds. The layer usually contains a polymer substance
that allows suitable organic compounds to be deposited. They
are deposited in rows and columns onto a flat carrier by a
simple "printing" process. The resulting matrix of pixels can
emit light of different colors.
Such systems can be used in television screens, computer
displays, portable system screens, advertising, information and
indication. OLEDs can also be used in light sources for
general space illumination, and large-area light-emitting
elements. OLEDs typically emit less light per area than
inorganic solid-state based LEDs which are usually designed for use as point-light sources.
A significant benefit of OLED displays over traditional liquid crystal displays (LCDs) is that OLEDs do not
require a backlight to function. Thus they draw far less power and, when powered from a battery, can operate
longer on the same charge. Because there is no need to distribute the backlight, an OLED display can also be
much thinner than an LCD panel. OLED-based display devices also can be more effectively manufactured
than LCDs and plasma displays. But degradation of OLED materials has limited the use of these materials.[1]
History
Bernanose and co-workers first produced electroluminescence in organic materials in the early 1950s by
applying a high-voltage alternating current (AC) field to crystalline thin films of acridine orange and
quinacrine. In 1960, researchers at Dow Chemical developed AC-driven electroluminescent cells using doped
anthracene.
The low electrical conductivity of such materials limited light output until more conductive organic materials
became available, especially the polyacetylene, polypyrrole, and polyaniline "Blacks". In a 1963 series of
papers, Weiss et al. first reported high conductivity in iodine-doped oxidized polypyrrole. They achieved a
conductivity of 1 S/cm. Unfortunately, this discovery was "lost"[clarify], as was a 1974 report of a melaninbased
bistable switch with a high conductivity "ON" state. This material emitted a flash of light when it
switched.
In a subsequent 1977 paper, Hideki Shirakawa et al. reported high conductivity in similarly oxidized and
iodine-doped polyacetylene. Alan J. Heeger, Alan G. MacDiarmid & Hideki Shirakawa received the 2000
Nobel Prize in Chemistry for "The discovery and development of conductive organic polymers". The Nobel
citation made no reference to the earlier discoveries.
Other companies
The Optimus Maximus keyboard currently in development by the Art. Lebedev Studio is expected to use 113
48×48-pixel OLEDs (10.1×10.1 mm) for its keys.
OLEDs can be used in High-Resolution Holography (Volumetric display). Professor Orbit showed on May
12, 2007, EXPO Lisbon the potential application of these materials to reproduce three-dimensional
video.[citation needed]
OLEDs could also be used as solid-state light sources. OLED efficacies and lifetime already exceed those of
incandescent light bulbs, and OLEDs are investigated worldwide as source for general illumination; an
example is the EU OLLA project.[36]
On March 11, 2008 GE Global Research demonstrated the first successful roll-to-roll manufactured OLED,
marking a major milestone towards cost effective production of commercial OLED technology. The 4 year,
$13 million research project was carried out by GE Global Research, Energy Conversion Devices, Inc and the
U.S. Commerce Department’s National Institute of Standards and Technology (NIST).
Commercial uses
OLED technology is used in commercial applications such as small screens for mobile phones and portable
digital audio players (MP3 players), car radios, digital cameras, and high-resolution microdisplays for headmounted
displays. Such portable applications favor the high light output of OLEDs for readability in sunlight,
and their low power drain. Portable displays are also used intermittently, so the lower lifespan of OLEDs is
less important here. Prototypes have been made of flexible and rollable displays which use OLED's unique
characteristics. OLEDs have been used in most Motorola and Samsung color cell phones, as well as some
Sony Ericsson phones, notably the Z610i, and some models of the Sony Walkman. It is also found in the
Creative Zen V/V Plus series of MP3 players. Nokia has also introduced recently some OLED products,
including the 7900 Prism and Nokia 8800 Arte.