For the past year, manufacturers have heralded OLED ultra-high definition (UHD) TVs as a harbinger of sea change in the home entertainment industry, affording thinner and even flexible panels with higher quality pictures than today's LCD sets.

Then last week, China-based TCL, the third largest manufacturer of flat-screen TVs in the world, disclosed plans to ship a 55-in quantum dot LCD TV, which offers the same quality picture as OLED, but at a one-third the cost.

Suddenly, OLED TVs, fewer than 500 of which shipped in the U.S. last year, appeared to be facing a nearly impenetrable foe.

The appeal of OLEDs: they offer deeper blacks and brighter whites than conventional LCD TVs. Essentially, such TVs offer more life-like images.

Unlike conventional LCD TVs, which require back lighting, OLED TVs use organic chemicals to generate the light can be produced in very thin films. The films are so thin that they can be printed out and enable flexible screens.

LCD quantum dot TVs maintain the current thickness of panels, so they're not flexible, but they do arguably offer nearly the same picture quality as OLED.

"LCD with quantum dot is a case of the good being the enemy of the best. It allows LCD indeed to close the gap with OLED," said Paul Gray, director of European research at DisplaySearch.

IHS Research predicts that around 14,000 OLED TV units will ship in the US during 2014, and that number will increase to almost 1.2 million units in 2018.

Quantum dot (QD) technology, a component added to existing LCD panels, allows manufacturers to offer the same full color spectrum touted by OLED, while maintaining their current manufacturing process.

Quantum-dot technology was first used commercially in 2013 by Sony in multiple flat-screen TV models. Now other TV and monitor makers, like TCL, are starting to follow suit.

Like OLEDs, quantum dot technology supplies light on demand, which enables more efficient displays than more common light emitting diode (LED) or liquid crystal diode (LCD) displays.

IHS analyst Veronica Gonzalez-Thayer has viewed quantum dot LCD TVs and said they do offer a life-like picture with "redder reds and greener greens" compared to standard LCD.

"The results are pretty much comparable with OLED in terms of color accuracy and a more vivid picture," she said.

High prices may sink OLED

Last month, LG announced it was shipping the world's first 4K (3840 x 2160-pixel resolution) OLED TV in 77-in and 65-in screen sizes. Both sets come as curved screens, which LG claims offers a better viewing experience. The 65-in model came with the staggering sticker price of $11,000.

While TCL doesn't expect to announce the price of its 55-in quantum dot LCD TV until it's available in November, DisplaySearch agrees the price should be vastly lower than OLED.

According to DisplaySearch, a 55-in conventional LCD TV costs about $400, a 55-in LCD TV with QD technology retails for about $500, while a 55-in OLED TV runs about $1,750.

The additional cost for OLED TVs can mainly be attributed to low manufacturing yields: about 40% of all production turns into scrap material, according to Gray.

"OLEDs are hard to manufacture in TV sizes. LG's selection of white OLED technology was at least manufacturable. Samsung discontinued OLED TV as over 90% of panels produced were defective," Gray said.

LG's OLED TVs add a fourth color - white - to the traditional red, green, blue color pallet offered by high definition TVs.

Quantum dot technology is a component mounted in the LCD backlight unit in front of a TV's blue LEDs (as opposed to white LEDs used by other manufacturers such as LG), according to Matt Mazzuchi, vice president of market and business development for QD Vision, maker of TCL's quantum dot technology.

Paul O'Donovan, a principal analyst with Gartner's Consumer Electronics Research unit, said quantum dot technology at the very least helps to lengthen the lifespan of LCDs as a big screen technology as the industry moves into 4K resolution and eventually beyond.

"That could be a significant factor in delaying OLED displays in terms of possible cost reduction in manufacturing as volume sales remain limited," O'Donovan said.

Toxic TVs

TCL's new 55-in. quantum dot display, developed with QD Vision Inc., is a light emitting technology that uses semiconductor nanocrystals similar to those in organic light-emitting diode (OLED) displays. But, the organic in "O"LED means it's carbon based, or non-toxic.

The displays built with quantum dot technology use a small quantity of cadmium sealed within the glass display to enhance colors. While sealed inside the glass display, cadmium is still a toxic heavy metal.

Cadmium is banned in many consumer appliances, but according to O'Donovan, there are non-cadmium quantum dot TV available as well, so "that shouldn't be an issue unless they are more expensive or not quite as efficient."

"However, I haven't seen QDs being proposed as an emissive display technology in their own right, which would be a direct competitor to OLEDS," O'Donovan added.

OLED TVs also suffer from the fact that there are still few companies developing the technology.

There's LG and Samsung doing it to some degree, but the only one really out there making them in volumes is LG," Gonzalez-Thayer said. "Even Chinese TV manufacturers aren't thinking about using LG's panels for OLED TVs."

"So, what's the consumer going to choose? The cheaper one," she said.