Ever since the beginning of the century, we find that the LCD TVs have picked up. Still, technology-wise these TVs are not efficient. Liquid crystals can pattern themselves in different ways depending on current. However, they cannot produce their own light. Thus every LCD screen requires back up light. They do need filters too. Ultimately, there is a loss of 80 per cent energy through light switches and colour filters. The other problems are the slow responsiveness and low contrasts. The advantage is that the technology is mature and scaled up so much that it is cost efficient. It is difficult to dislodge it fast.

The alternative technology is being tried is OLED. It entered the market 15 years back. OLED stands for Organic Light Emitting Diodes. It is an organic material that is soft. It can be spread thin. If a TV screen is made of OLED, it can be as thin as a wall-paper. These screen offer superior colour quality. The picture can be viewed from  any angle. It has high contrast. As OLEDs are soft, these can be made to bend. In future, there could be foldable and flexible screens.

Still, these are early days for this technology. It is expensive. Its manufacturing process is being researched. The cost will come down. The present technology uses glass substrate. It is being tried to replace it with silicon substrate. That integrates it well to the electronics. It will take a few years to commercialise the research.

Already OLGD TVs are available from LG and Samsung. They have mastered the art making flexible substrates to remove rigidness of glass substrate.

Other competing technology is that of quantum dots. These are organic materials which emit light superbly. They provide better colour purity than OLEDs. Still the technology is on the drawing board stage. It is not ready for commercial use. The search for better light emitters is continuously on. One mineral perovskite has shown potential. Technologies mature over a period of 15 -20 years. Such future technologies are still far off.