Difference Between AMOLEDs And TFTs (With Table)

The use of technological devices is an invincible part of our lives. The simplest of simple works like talking, walking, listening can now be done by technological devices like Mobile phones, TV, Desktop computers.

These devices have gone through a lot of evolutions in past years. One such is display screens. AMOLED and TFTs are a part of such innovation.

AMOLEDs vs TFTs

The main difference between AMOLEDs (Active Matrix Organic Light-Emitting Diodes) and TFTs(Thin-film transistors) is the materials. AMOLEDs use Organic material, mainly, carbon, whereas TFTs do not use organic materials. AMOLED has a brighter display in comparison to TFTs.


AMOLEDs (Active Matrix organic light-emitting diodes) are the enhancements made in conventional OLED displays. They generate light by applying current to semi-conductive organic materials. It works on each pixel by pixel illumination and color controlling according to needs .AMOLEDs also have a layer of TFTs. The TFTs results in an “Active Matrix” of lights in AMOLEDs.


TFT is a type of field-effect transistor in LCDs .Hence, TFTs are more common in TV, desktop computers, etc.,. TFT uses current controlling transistors in each pixel. TFTs act as individual switches that allow the pixels to change state rapidly. As TFTs are laid out in a matrix, they are also called “active-matrix”.

Comparison Table Between AMOLEDs And TFTs

Parameters of ComparisonAMOLEDsTFTs
Full formActive Matrix Organic Light- Emitting DiodesThin Film Transistor
MaterialsAMOLEDs use organic material mainly, carbon to emit light.They do not use organic material to emit light.
Light GenerationThey generate their own light.They can’t generate their own light and hence, rely on backlight.
DisplayAbsence of backlight makes them thin and hence have better color quality.Presence of backlight makes them thick and so color quality is low.
Power-ConsumptionAMOLEDs have less power consumption.TFTs have more power consumption
Life-SpanAMOLEDs have less life span.Their life span is more than AMOLEDs
Response TimeThey have faster response timingTheir response timing is slow
CostThey are very costly.They are cheaper than AMOLEDs

What is AMOLED?

An OLED display was in use till 2006, when AMOLEDs were discovered. The first technological device with AMOLEDs was a Samsung Galaxy Note. OLEDs(Organic light-emitting diodes) were a huge evolution after conventional LCD(liquid crystal diode).

OLEDs generated light by applying current to semi-conductive organic material. This organic material for the most part is carbon. These organic materials have the ability to work at small scales, such that they can work on each pixel by pixel to illuminate light. They enable each pixel in the display to get brighter or darker according to the needs.

These colors were displayed by using organic materials which have the caliber to produce light of specific wavelengths(colors).AMOLEDs(Active-matrix Organic light-emitting diodes) were an enhancement made in OLEDs. An extra layer of TFTs was added in OLEDs. This layer of TFTs offers greater control over light emitted by OLEDs.

Because of this display could be brighter and provide greater contrast. It consumed less power and hence, proved to be a better display. Initially, this technology was restricted to mobile phones, but with the better display is now also used in technological devices apart from phones, like TV, Desktop computers, Laptops.

Despite, all these positive traits AMOLEDs also have some negative traits which do not make it the right choice. Some organic materials have a shorter lifespan hence, AMOLEDs can’t be used in devices that demand a larger life span. Also, the presence of both TFTs and organic materials makes it quite expensive.

What is TFT?

TFT (Thin Film Transistor) is a sort of Field Effective transistor(FET).FET is a three-terminal device used for various applications as Bipolar Junction Transistor.

Current conduction in FET takes place by only one type of charge carrier, holes in the p channel, and electrons in the n channel. TFTs were built by keeping thin films of the active semiconductor layer by layer. A dielectric layer along with a glass substrate is also used in making layers.

TFT was discovered in laboratories in 1968. By 1971, it came into use in technological devices as display alongside LCDs(Liquid crystal Display).LCD contains a backlight that illuminates individual pixels arranged in a rectangular grid, called a matrix. After the discovery of TFTs, they were used along with LCDs.

These TFTs had capacitors which would help to retain the charge actively in each pixel. Hence, these TFTs were also called “Active Matrix”. Hence, the name in AMOLEDs. So, this innovation was much better than conventional LCDs.

Earlier LCDs display was restricted to technological devices like desktop computers, TV but the better display of active-matrix LCD demanded usage of LCDs in mobile devices like Laptops, Smartphones, Tablets.

Even though there are many evolutions after the discovery of TFTs, their pocket-friendly cost, as well as longer life span, makes them one of the most common choices in displays.

Main Differences Between AMOLED And TFT

  1. The full form of AMOLEDs is an Active Matrix Light-Emitting Diode whereas the full form of TFTs is Thin Film Transistor.
  2. AMOLEDs were an improvement made in OLEDs which use organic material predominantly carbon to generate light. TFTs do not use any organic material.
  3. AMOLEDs can generate their light by generating current through organic materials while TFTs use LCDs which use backlight to illuminate each pixel.
  4. AMOLEDs have better color quality because of organic materials of different wavelengths which produce brighter colors. On the other hand color quality in TFTs is low.
  5. TFTs have a layer of the backlight that makes them thick hence power consumption is more than AMOLEDs.
  6. Presence of organic materials makes the life span of AMOLEDs shorter. Whereas TFTs have a longer lifespan.
  7. AMOLEDs have a layer of TFT which makes them quite expensive, while TFTs are quite pocket-friendly.

Conclusion

Both TFTs and AMOLEDs are in demand for displays of technological devices. TFTs were an innovation made after conventional LCD, which used backlight to illuminate each pixel.

After the discovery of TFTs, they were used alongside LCD. These TFTs would retain charge more actively in each pixel. Hence they were also termed as “Active Matrix”

AMOLEDs are formed of both TFTs(AM; Active Matrix) and OLEDs .OLEDs illuminated each pixel by pixel by generating current through organic materials. A layer of TFT was added in AMOLEDs such that it could actively charge each pixel.

Because of this, AMOLEDs have a better display and can produce brighter and contrasting colors in comparison to TFTs. TFTs use backlight which makes them thick and hence power consumption is more in TFTs.

AMOLED has less life span due to the presence of organic materials, which also makes it quite expensive whereas TFTs are quite pocket-friendly.

References

1. https://ieeexplore.ieee.org/abstract/document/1295107

2. https://ieeexplore.ieee.org/abstract/document/4066878