Samsung is touting QLED as the next big TV technology. But what is it? How does it work? And is it better than OLED? Read on, and all will be revealed.

OLED is still a pretty young picture technology, yet people are already talking about what some - notably Samsung - think will be its successor: QLED.

So what does the technology involve? How is it different from OLED? And when will it launch in the UK? Read on for our comprehensive guide.

MORE: What is OLED? The tech, the benefits, the best OLED TVs

What is QLED?

QLED stands for Quantum dot Light Emitting Diode. It aims to be the next step on from OLED which, in turn, tends to deliver superior performance compared with LCD.

At the moment, only LG and Panasonic sell OLED TVs in the UK, though Sony launched its own range at CES 2017. OLED tellies are much slimmer than LCD or plasma sets, with much wider viewing angles and superior contrast ratios.

QLED promises to improve picture quality yet further, without sacrificing the deep blacks of OLED sets.

More after the break

How does QLED work?

It works using quantum dots. This technology itself isn't new - Samsung's SUHD TVs use quantum dots, for example - but QLED uses it in a new and interesting way.

Quantum dots are microscopic molecules that, when hit by light, emit their own coloured light. The colour they emit depends on their size - larger ones give off light at the red end of the spectrum, smaller ones at the blue end. (They're only nanometers in size, which is a fraction of the width of a human hair. So when we say "larger", it's all relative.) 

Current TVs use photoluminescent quantum dots, whereas QLED TVs use electroluminescent ones. Basically, instead of requiring the light from an LED in order to light up (as photoluminescent quantum dots do), electroluminescents use directly supplied electrons to generate light.

This lets the TV light up and turn off individual pixels, just like an OLED set, making for an infinite contrast ratio.

Quantum dots supposedly give off incredibly bright, vibrant and diverse colours, making them well suited to showing off HDR content. And, crucially, it's reckoned to be a more cost-effective technology than OLED.

In other words, a QLED set could be able to match or improve on the picture quality offered by OLED, and at a cheaper price. That's the theory, at least.

As it stands, though, quantum dots are a mixed bag. In our review of the quantum dot-enabled Samsung UE65KS9000, for example, we noted that the black levels could go deeper, and that there was a slight issue with backlight banding. But overall the set was superb, delivering one of the most lifelike pictures we've seen from an LCD panel.

It's worth remembering this is only the start for quantum dot technology. Based on our experience so far, the future looks bright. Literally.

MORE: Best OLED TV deals

How does it compare to OLED?

Until we see QLED TVs on the market and get them in for review, it's impossible to say for sure. 

But the claim is the technology should make for a brighter picture than OLED, and deliver a wider colour gamut. Combine that with the existing, impressive contrast ratio, and you should have a striking viewing experience.

In fact, it's estimated QLED screens could have 30-40 per cent more luminance efficiency, which would make for brighter pictures and hopefully more vivid colours.

Then there's the price. OLED TVs are still very expensive. You're currently looking at just under £2,000 for a 55-inch OLED set, and that's one of the more reasonably priced. However, QLED sets should cost less to produce, so we're hoping the manufacturers will pass the savings onto customers. Bring on the price war...

QLED TVs use roughly half as much power as OLED screens, making them cheaper to run. You might not think that makes a big difference, but running a telly can be an expensive business.

Recently, British Gas claimed 4K TVs are costing British homes an extra £1.8m in electricity costs because they use more power than non-4K sets. This figure is expected to rise to as much as £82m by 2019. So a more efficient TV would be most welcome.

MORE: 4K, HDR, OLED: The 7 best TVs of the year

When will QLED come to the UK?

Samsung is the only major manufacturer to have announced a QLED range so far. It's so confident in the technology, it has leapfrogged OLED altogether. 

However, according to the Korea Times LG is also ramping up its QLED research. It's started working with the leading lights (no pun intended) of the QLED world, including Nanoco, Nanosys and QD Vision in order to learn more about the technology.

It has launched a group-wide project to boost cooperation among its affiliates, LG Electronics, LG Display and LG Innotek, for research on QLED TVs. And it recently developed quantum dot sheets, which can be used for LCD-based quantum dot TVs. It could use this product category as a stopgap before producing proper QLED tellies.

So when will we get to experience QLED? Samsung took the wraps off its ranges at CES 2017 - these are the flagship Q9, Q8 and Q7. In February, these were made available to pre-order in the US, with prices starting at $2,500 (£2,000). That's not cheap, especially given the company still hasn't revealed exactly how much the flagship Q9 will cost.

Samsung's sets were supposed to ship in late February, but with that date having come and gone, there's still no word on when they'll reach the UK. QLED is a whole new ball game, so there's a chance production could cause some issues - the manufacturing technologies required haven't yet been prepared or perfected, after all. The process is also not yet free of cadmium materials, which are extremely toxic. Samsung suffered enough reputational damage with its exploding Galaxy Note 7, and really won't want to make any mistakes with a new TV technology.

LG also doesn't expect QLED to arrive anytime soon. The firm is looking at QLED in a "long-term perspective", but considering it has five new ranges of OLED tellies for this year, that's perhaps no surprise.

At the moment, QLED is used mainly for entertainment and architectural lighting. But if giants such as Samsung and LG start releasing QLED sets, and they're as good as they could be, expect plenty of other TV manufacturers to follow suit.

MORE: LG OLED55B6V review

MORE: Samsung 2017 TV line-up