LED, OLED & QLED Technology
When it comes to video displays, in particular, there is one piece of technology that can be incredibly useful to understand as a consumer: LEDs. Thankfully, they are simpler than their full name (light-emitting diode) makes them sound, especially for the purposes of being a savvy consumer.
What are LEDs?
An LED is a tiny device made of a semiconductor or a material that conducts electricity better than an insulator, but worse than a conductor. Silicon is a common example of a semiconductor used in electronics. When electricity passes through an LED, the material emits light. Different materials emit different colored lights, so if you put a tiny crystal of three or four different semiconductors in a single LED, you have a device that can produce whatever color of light you need it to, due to the way different colored lights blend together in our eyes to show us the combination of those colors.
QLED vs. OLED
There are two main, competing technologies in the field of LED displays, and knowing the pros and cons of each is the key to buying the right display for your needs. These technologies, QLEDs, and OLEDs, not only use different types of LED technology to create their displays, but they also employ them differently.
QLEDs
QLED is a marketing term for QD-LED, or quantum dot LED. A quantum dot is simply a very small semiconductor dot that works like the semiconductors in an LED: when charged, it produces colored light. The difference is that the QDs in QLED TVs are charged by light rather than electricity. A backlight made of blue LEDs shines into the quantum dot layer, causing the dots to emit purer, brighter colors than the LEDs themselves could. A common use for this technique is in LED-backlit LCD displays. The LED backlight is filtered through quantum dots to be as pure white as possible, improving color quality in the resulting display. Most QLED televisions use this setup.
OLEDs
OLED stands for organic LED, and refers to the fact that the semiconductor used in these LEDs is an organic compound. Rather than being used as a backlight for an LCD display, OLEDs are used as pixels in their own right, receiving electricity and producing bright, clear colors directly for the screen.
Mechanics aside, these two technologies perform differently when used for the same purposes, and those differences are why we see these acronyms in our search results when shopping for anything with a screen. As a general rule, OLEDs produce a higher quality image, but are more expensive than QLEDs. Because QLEDs are the latest iteration of the LCD screens that have dominated the market for a long time now, they are a very mature technology, and are thus cheaper to produce and quite efficient. OLEDs have had less time to be perfected, and are mainly a competitor because of the advantages in quality they offer over QLEDs, even if they are more expensive.
There are two main things that OLEDs do much better than QLEDs: black level and viewing angle. With a QLED display, the color black is displayed by the screen blocking out the light coming from the LED backlight. This results in a fairly imperfect black, though the quantum dots themselves can help improve the color quality compared to a non-QD LCD. With OLEDs, black can be displayed simply by not powering the pixels in question, resulting in top quality black levels, as there is no light at all coming from that region of the screen.
Viewing angle is not something that often comes into play when you’re just watching TV at home, or using your phone, or working on a laptop. When there is only one person and they are in full control of the position of themselves and the display, they can arrange both so they are looking directly at the screen. But if you’re having a football party, the TV is mounted over a bar, or your screen is so large it can’t be moved easily, viewing angle matters. QLEDs appear darker if you are too far to one side of the display, and the effect intensifies the farther away from the focal point you move. By contrast, OLED displays can be viewed with the same brightness from almost anywhere you can see the screen.
Most companies that make screens of any kind will offer both QLED and OLED options, since the technologies for both are manufactured and sold to other businesses for use in their own products. When considering which of the two you should spring for, the most important differences to remember are price and image quality. QLEDs are going to be better for your budget, and are less susceptible to burn-in than OLEDs (burn-in is when a screen that displays a static image for a long time starts to show a “ghost” of that image even while displaying other media). OLEDs on the other hand offer better color accuracy and a wider viewing angle. Both are appealing options, and the choice you make between them depends more on your specific needs than anything. In short, QLEDs are more cost-efficient and reliable, while OLEDs are more accurate and versatile.
