What is LTPS LCD? What are the Pros and Cons?

What is LTPS LCD? What are the Pros and Cons?

An LTPS LCD is a type of liquid crystal display that uses low-temperature polysilicon as the major component of its thin-film transistor. More specifically, it is not a particular LCD technology like in-plane switching or twisted nematic, but rather, it is a backplane technology similar to indium gallium zinc oxide or IGZO TFT and amorphous silicon or a-Si TFT technologies.

Understanding the Pros and the Cons

The following are the advantages and applications of LTPS LCD:

• Better electron mobility or faster electron flow is a key advantage of low-temperature polysilicon. Electrons flow 100 times faster in this material than in amorphous silicon and around 10 times faster than conventional indium gallium zinc oxide.

• Electron mobility translates to pixel response time and pixel density. Hence, a major application of LTPS is in designing and producing LCDs with higher resolutions and faster pixel response time. This backplane technology is more suitable for in-plane switching LCDs and mini-LED LCDs.

• The material ranks first in energy efficiency, followed by IGZO and then a-Si. It consumers less power because it has better electron mobility and requires fewer components. Note that the number of components in a low-temperature polysilicon liquid crystal display can be reduced by up to 40 percent.

• Another application is in portable consumer electronic devices that require small and flexible display panels. Researchers are investigating specific applications in flexible and curved LCD panels. However, more studies are needed to address engineering and fabrication issues.

Below are the disadvantages and limitations of LTPS LCD:

• Note that it has a more complicated manufacturing process and higher manufacturing cost than amorphous silicon. This is a notable disadvantage. Essentially, a liquid crystal display based on low-temperature polysilicon is more expensive to produce, thus translating to a higher price point than a-Si TFT LCDs.

• It is also sensitive to high temperatures and susceptible to overheating. Heat can breakdown the silicon-hydrogen bond on the material and degrade the overall thin-film transistor. Fundamentally, it has a shorter lifespan than amorphous silicon, with quality degrading at a faster rate.

• An alternative to LTPS LCD is IGZO liquid crystal display. A specific array of indium gallium zinc oxide could be designed to have electron mobility that could be near as low-temperature polysilicon. An IGZO display can retain an active pixel state for a longer period compared to both LTPS and a-Si that necessitate continuous pixel refresh because of their high current leakage.


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