Disclaimer: The article is copied fro WhatHiFi for public knowledge – Link: https://www.whathifi.com/advice/oled-vs-qled-which-best-tv-technology
We illuminate the bright lights and gloomy darks of OLED and QLED TV screens
‘OLED’ and ‘QLED’ are the two biggest acronyms in TV panel tech, and while they sound very similar, they are in fact very different indeed.
‘OLED’ stands for ‘Organic Light Emitting Diode’ while ‘QLED’ is ‘Quantum Dot Light Emitting Diode’, and you’ll find that the vast majority of the best TVs feature one or the other.
So which is best? That depends on a number of factors, including how well it’s been implemented in the specific TV you’re looking at and on your personal picture preferences.
Let’s get into the nitty-gritty.
OLED pros and cons
OLED (Organic Light-Emitting Diode) is a type of display tech that consists of a carbon-based film through which two conductors pass a current, causing it to emit light.
Crucially, this light can be emitted on a pixel-by-pixel basis, so a bright white or coloured pixel can appear next to one that’s totally black or an entirely different colour, with neither impacting the other.
This is in direct contrast to a traditional LCD TV, which relies on a separate backlight to generate light that’s then passed through a layer of pixels.
Despite many attempts over the years, no TV with a backlight has ever managed to completely eradicate the issue of light bleeding from an intentionally bright pixel to those around it.
Other advantages of OLED are that the panels are lighter and thinner than a typical LCD/LED arrangement, viewing angles tend to be significantly wider, and response times can be supremely quick.
One disadvantage is that OLEDs are comparatively expensive to produce. Prices are steadily getting more realistic – thanks in no small part to LG Display (currently the largest producer of OLED panels for TVs) selling panels to other manufacturers such as Sony, Panasonic and Philips, increasing both the number of OLED TVs being produced and competition in the shops – but OLED TVs still tend to be a fair bit more expensive than most standard LCD models.
Sizes can be an issue where OLEDs are concerned. Until very recently, you couldn’t buy an OLED TV smaller than 55 inches. 48-inch OLEDs appeared for the first time in 2020, with the excellent LG OLED48CX leading the way, and 2022 saw the launch of the first 42-inch OLED TV, the LG OLED42C2. However, as these ‘small’ OLEDs are currently produced in relatively low numbers, they tend to be barely any cheaper than their 55-inch equivalents. The panels also tend to have lower peak brightness than the latest, brightest, bigger sets, arguably making them less good value.
OLEDs in general have typically struggled to offer the sort of brightness that a top-notch QLED can manage, but new MLA and QD-OLED technologies have now upped OLED brightness significantly.
MLA, represented by models such as the LG G3 and Panasonic MZ2000, features a so-called Micro Lens Array that focuses the light from the OLEDs so that the TV’s image is much brighter without the organic materials themselves needing to be pushed any harder.
QD-OLED, which you’ll find used in models such as the Samsung S95C and Sony A95L, combines Quantum Dots with Organic Light Emitting Diodes to improve colour vibrancy and increase contrast.
However, most OLED TVs still feature ‘standard’ OLED panels and are sometimes referred to as WOLED TVs on account of their use of a white sub-pixel. These are limited in terms of brightness compared with their MLA-OLED and QD-OLED counterparts – not to mention many QLEDs – but they’re still bright enough for most people and home viewing environments and, thanks to their perfect blacks and pixel-level contrast control, generally produce stunningly punchy results.
Finally, no discussion of OLED technology could be complete without a mention of burn-in. The organic nature of an OLED panel means it is potentially susceptible to image retention and even burn-in, in a similar way to the plasma TVs of old. This really doesn’t seem to be a widespread problem, though. We have never had image-retention problems with any of the OLEDs that we have tested (or the models that staff members have bought for use at home) and manufacturers do build-in features to reduce the risk.
That said, those manufacturers do still feel the need to warn customers about the potential for image retention either in the TV’s manual or as a pop-up message on first installation, so make of that what you will.
QLED pros and cons
While it may be aboard the OLED train now, for many years Samsung avoided the technology, instead promoting a rival named QLED. Although QLED has mostly been associated with Samsung, it is worth noting that other manufacturers, such as Hisense, Vizio, TCL and even Amazon, also use the technology, though sometimes under a different name.
QLED stands for Quantum-dot Light-Emitting Diode which, in theory at least, has a great deal in common with OLED, most notably in that each pixel can emit its own light, in this case thanks to quantum dots – tiny semiconductor particles only a few nanometres in size.
These quantum dots are (again, in theory) capable of giving off incredibly bright, vibrant and diverse colours – even more so than OLED.
The problem is that the quantum dots used in current commercially available QLED TVs do not in fact emit their own light. Instead, they simply have the light from a backlight passed through them, in just the same way that an LCD layer does on standard LCD/LED TVs.
In the future, this will probably change. A number of self-emissive QLEDs have already been displayed at industry events, including the world’s first 8K self-emitting QLED display designed by BOE. Unlike traditional QLEDs, which use a quantum dot film sandwiched between an LED backlight and an LCD panel, BOE’s self-emissive QLEDs contain quantum dot nanocrystals that can produce their own light when placed in an electric field. This means that, as with OLED, it doesn’t require a backlight, and each pixel can be individually dimmed.
Domestic self-emissive QLEDs are still a way off, however. In the meantime, traditional quantum dots still improve colour vibrancy and control over LCD, narrowing the gap to OLED, but this isn’t yet the next-gen, game-changing technology that Samsung has always suggested with its QLED branding.
OLED’s ability to light each pixel individually gives it an undeniable advantage over QLED. While overall brightness levels are lower, contrast is still incredibly impressive.
Samsung has sought to increase the contrast of its QLED models by switching from standard LED backlights to Mini LED backlights for its most premium models, which it refers to as ‘Neo QLED’ TVs. As the name suggests, these backlights use much smaller LEDs – they genuinely resemble sparkly grains of sand – that can be packed in in far higher quantities. By increasing the number of LEDs, the number of independent dimming zones can also be increased, resulting in significantly greater contrast.
The flagship Samsung QN95C, for example, is thought to have more than 1300 independent dimming zones (Samsung doesn’t confirm specific numbers). Of course, because every pixel of an OLED TV can be controlled independently, it essentially has more than eight million independent dimming zones, but the new Neo QLEDs are clearly a step towards sets that combine the contrast of OLED with the brightness and longevity of backlit sets.
But things get really exciting when we look forward to those next-gen quantum dots that will be capable of emitting their own light. These photoluminescent quantum dots with the ability to light up and turn off individual pixels theoretically retain the advantages of greater vibrancy and brightness.
Unfortunately, it looks as though consumer TVs that will use these new quantum dots are still a long way off. And, with Samsung’s portfolio of screen technologies expanding to include QD-OLED and MicroLED, advancement in the field of emissive QLED may come only through competition from other manufacturers getting involved to push forward the progress of the next-gen screen technology.
In the meantime, one big advantage for QLED is cost, as QLED TVs routinely cost significantly less than OLEDs. Quality is variable, to say the least, and a ‘cheap’ QLED won’t deliver the same sort of performance as a flagship Samsung such as the QN95C, but Amazon’s Omni QLED proves you can get a good QLED TV for a surprisingly low price, while TCL’s C845K offers hundreds of dimming zones and a peak brightness figure double that of a typical OLED TV for under £1000.
Final verdict
It’s going to be a while before MicroLED is a realistic proposition for most people and self-emissive quantum dots are even further away. While QD-OLED TVs may blend some of the qualities of QLED and OLED, they haven’t yet proven to be the best of both worlds with the Sony A95K and Samsung S95C putting in brilliant but not game-changing performances.
With TV tech inevitably improving year by year, a TV buyer in the here and now is forced to choose which combination of strengths and compromises best suits their taste.
Flagship QLEDs from Samsung (and some others) absolutely deliver a brighter and punchier picture than their OLED rivals, and in recent years they have impressively closed the gap in terms of black depth and viewing angles. Recent Mini LED-backlit Neo QLEDs are yet another step in that direction.
OLED still has an advantage in these regards, though, and while OLED TVs don’t go as bright as QLEDs, their self-emissive properties make for absolutely stunning contrast.
One other thing to bear in mind is that the panel technology used is only one part of the picture puzzle, with a set’s processing making a big difference to performance. That’s why OLEDs from LG, Philips, Panasonic and Sony all look different in action. Some are punchier, others sharper; some offer richer colours while others are better at handling motion. In other words, you can’t simply go out and buy the first OLED you see. You should instead consult our guide to the best OLEDs you can currently buy.
All QLEDs sold by Samsung differ from model to model, too; not so much in terms of processing, but in terms of key specifications such as the brightness and number of dimming zones of the backlight. To get the punchiest QLED with the most dimming zones, you have to go for the 4K QN95C or go up to an 8K model. Our Samsung 2023 TVs page has all of the details. Do also check out the TCL C845K, which is exceptional value.
The long and short of it is that OLED and QLED are both capable of exceptional results, and you are probably best off not setting your sights on a specific technology and instead simply looking for the best overall TV you can afford. Our guide to the best TVs you can currently buy should help in that regard.
(Article by Tom Parsons)