Organic Light-Emitting Diode (OLED) is a technology that employs LEDs to produce light that is produced by organic molecules. These organic LEDs are utilized to make what is widely regarded as the best display panels in the world.
In this blog, we are discussing the basics of OLED, its Types, Advantages, Disadvantages & Applications in detail
What is an OLED?
OLED stands for Organic Light Emitting Diode, and it is made up of individual image elements called pixels comprises of organic chemical compounds that emit light when an electric current is supplied between their anode and cathode. Light is emitted through the recombination of electrons and holes from the cathode and anode in this process, which is similar to that of a normal LED.
OLEDs provide for emissive displays, in which each pixel is individually controlled and generates its own light (unlike LCDs in which the light comes from a backlighting unit). OLED displays have excellent image quality, with vibrant colors, quick motion, and, most significantly, strong contrast. Specifically, “real” blacks (that cannot be achieved in LCDs due to the backlighting). Because of the simple OLED design, flexible and transparent screens are relatively easy to build.
OLED Device Structure
The basic structure of an OLED is simple: an organic emitter is sandwiched between two electrodes. Commercial OLEDs, on the other hand, utilize multiple intermediate layers, such as electron transport and blocking layers, to make efficient and long-lasting devices. Between the electrodes, the entire organic stack is inserted, and the entire structure is deposited on the substrate (glass or plastic) and the display backplane (driver electronics). Some OLED panels on the market have dozens of layers stacked on top of each other.
Types of OLED
- Passive-matrix OLED
- Active-matrix OLED
- Transparent OLED
- Top-emitting OLED
- Foldable OLED
- White OLED
- Passive-matrix OLED (PMOLED)
PMOLED is made up of cathode strips, organic layers, and anode strips. The anode strips are parallel to the cathode strips and are positioned perpendicularly. The pixels where light is emitted are formed by the junctions of the cathode and anode. External circuitry controls the flow of current through selected anode and cathode strips, selecting which pixels are turned on and which remain off. Each pixel’s brightness is related to the quantity of current applied.
PMOLEDs are simple to manufacture, but they use more energy than other varieties of OLEDs, due to the power required for the external circuitry. PMOLEDs are most suited for small screens (2 to 3-inch diagonal), such as those seen in cell phones, PDAs, and MP3 players, and are most efficient for text and icons. Passive-matrix OLEDs use less battery power even with additional circuitry than the LCDs that now power similar devices.
- Active-matrix OLED (AMOLED)
AMOLEDs have full layers of the cathode, organic molecules, and anode, but the anode layer is layered over a matrix of thin-film transistors (TFTs). The circuitry that determines which pixels are switched on to generate an image is called a TFT array.
Because the TFT array consumes less power than external circuitry, AMOLEDs utilize less power than PMOLEDs, making them more efficient for big screens. AMOLEDs also offer higher refresh rates, which make them ideal for video. Computer displays, large-screen TVs, and electronic signs or billboards are the best usage for AMOLEDs.
AMOLED is now used by Samsung, Oneplus, and a slew of other high-end brands.
- Transparent OLED
When turned off, transparent OLEDs have solely transparent components (substrate, cathode, and anode) and are up to 85% transparent to their substrate. When you turn on a transparent OLED display, light can pass in both ways. An active-matrix or passive-matrix transparent OLED display is available. Heads-up displays can benefit from this technology.
- Top-emitting OLED
Top-emitting OLEDs have a substrate that is either opaque or reflective. They are best suited for active-matrix design. Manufacturers may use top-emitting OLED displays in smart
- Foldable OLED
The substrates of foldable OLEDs are made of highly flexible metallic foils or polymers. They are both lightweight and long-lasting. Their use in devices like cell phones and PDAs can help to decrease breakage, which is a common reason for returns and repairs.
Foldable OLED screens could be stitched into fabrics to make “smart” clothing, such as outdoor survival apparel with a built-in computer processor, cell phone, GPS receiver, and OLED display.
You’ve probably heard of Samsung’s Galaxy Fold, Motorola’s Razr, and a slew of other folding phones. They both make use of the same technology.
- White OLED
White OLEDs produce a brilliant white light that is uniform and more efficient than fluorescent lighting. In addition, they have the same true-color properties as incandescent lights. Because OLEDs can be manufactured in big sheets, they can be utilized to replace fluorescent lights in homes and buildings. Their use could potentially lower lighting energy expenses.
Advantages of an OLED DIsplay
- OLED displays are self-emitting light sources
- Does not require a separate external light source to produce an image
- More effective than TFT LCD Display
- OLED displays are substantially thinner than other technologies due to their self-illumination
- Superior viewing angle
- High brightness and contrast
- Fast response time
- Small size form factors
- Well suited for battery-driven applications
Disadvantages of OLEDs
- Shorter lifetime than some other display technologies. This shorter lifetime is mainly due to the blue organic material but life gets better all the time but is also due to moisture migration.
- Water can easily damage OLEDs.
- Manufacturing processes are expensive right now.
- Their lifetime is shorter compared to other display types. White, Red, and Green OLED offer a lifetime of about 5 to 25 years whereas blue OLED offers about 1.6 years.
- OLED screens are even worse compared to LCD when subjected to direct sunlight.
- Overall luminance degradation.
- Limited market availability.
Applications of OLED
OLED devices’ self-emissive properties allow for the creation of extremely efficient and lightweight display designs. They’ve been used in a variety of end-use applications because of their tremendous versatility, including:
- Televisions and monitors
- Smartphones and tablets
- Wearable devices
- Light panels
- OLED materials from Avantama
- Audio Systems
Hope this blog helps you to understand the basics of OLED Display, Its construction, advantages and disadvantages, and applications. We, MATHAELECTRONICS will come back with more informative blogs.