12 · Self-emissive
QD-OLED & the blue light that becomes every color
QD-OLED keeps the part of OLED everyone loves, a pixel that makes its own light and switches fully off for perfect black, and fixes the part white OLED had to fake. Instead of a white pixel pushed through color filters that throw away most of the light, QD-OLED starts with a pure blue OLED, the highest energy light in the visible range, and lays a sheet of quantum dots over it. A quantum dot is a crystal so small that its size sets the color it glows. Blue light landing on a larger dot comes back red, on a smaller dot comes back green, and the blue subpixel just lets the source light pass. Nothing is thrown away by a filter, so the color comes out purer and brighter, which is why QD-OLED posts the widest color and the highest color brightness of any panel you can buy today.
One sheet of blue OLED glows underneath all three subpixels. Red and green subpixels carry quantum dots that soak up that blue and re-emit it as red or green, while the blue subpixel just lets the source through. Turn the dots off to see what the bare blue source looks like, or pick a part to read its job.
Station 01
Why converting beats filtering
White OLED makes one strong white light and then puts red, green and blue filters in front of it. A filter makes color by absorbing the parts of the light it does not want, so each colored subpixel throws away roughly two thirds of what reached it, and a fourth clear white subpixel is added just to win some brightness back. QD-OLED never blocks light to make color. The blue source is recycled into red and green by the dots, so far more of it reaches your eye. Flip between the two and watch the light budget.
Station 02
Color that stays bright
Peak brightness on a white test patch is the number on the box, but it hides the real story. When you push a deep color toward its brightest, a filtered panel has to lean on its white subpixel, so the color washes out toward white. QD-OLED holds its color because the dots keep emitting pure red and green even at high drive. Raise the brightness and watch a saturated patch on each panel.
Station 03
The bright-room catch
A white OLED panel stacks a polarizer and color filters that quietly soak up room light, so its black stays dark even with a lamp on. QD-OLED skips that stack, and the bare quantum dot layer is happy to glow a little when stray light hits it, so in a bright room the black lifts to a faint purple-gray. In a dark room you never see it, and the color advantage stays. Raise the room light and compare.
Station 04
QD-OLED against its neighbors
QD-OLED and white OLED are the two ways a self-emissive TV gets made today, and a quantum dot LCD is the bright backlit alternative. Each wins something. Tap a column.
| Trait | QD-OLED | White OLED | Quantum dot LCD |
|---|---|---|---|
| Makes its own light? | Yes, blue per pixel | Yes, white per pixel | No, shared backlight |
| How it makes color | Blue into red and green dots | White through color filters | Backlight through dots and filters |
| Black level | Perfect in the dark | Perfect in the dark | Dark gray, depends on dimming |
| Color volume | Best in class | Very good | Very good |
| Brightness of color | Holds color when bright | Leans on white subpixel | Very bright, can wash out |
| Black in a bright room | Lifts to faint purple-gray | Stays dark, filters help | Dark gray with blooming |
| Burn-in risk | Possible over years | Possible over years | None |
| Where it shines | Dark-room monitors and TVs | Bright living rooms | Bright rooms and big sizes |
The tradeoff
What QD-OLED nails, and where it still pays a price
QD-OLED takes the self-emissive black of OLED and adds the purest, brightest color of any panel on sale. The bill comes due in a bright room, in a coating that scratches, and in the same slow wear that every organic emitter carries.
Strengths
- The widest color and the highest color brightness you can buy, because dots convert blue light instead of blocking it.
- Perfect black and per-pixel control in a dark room, the self-emissive trait it keeps from OLED.
- Wide viewing angles with no color shift, since there is no filter stack tinting the edges of the picture.
Weaknesses
- In a bright room the black lifts to a faint purple-gray, because there is no filter stack to soak up stray light.
- The anti-glare coating is soft and picks up scratches more easily than a white OLED panel.
- The blue source still ages, so burn-in is possible over years of the same static content.
Questions
QD-OLED, quick answers
Does QD-OLED burn in?
It can, for the same reason any OLED can. The light still comes from a blue organic emitter that ages with use, and a bright static logo or game bar left onscreen for thousands of hours can wear those pixels faster than the rest. Pixel shifting, logo dimming and refresh routines hold this off well for normal mixed viewing, so most owners never see it.
Why do QD-OLED blacks look a little purple in a bright room?
A white OLED panel hides a polarizer and color filters that soak up room light, which keeps its black dark under a lamp. QD-OLED skips that stack to save light, so when stray room light lands on the bare quantum dot layer it glows back a touch, and the black lifts to a faint purple-gray. In a dark room the effect is gone and the color lead stays.
Is QD-OLED better than white OLED?
For color it is the clear winner, with purer and brighter color that holds up as the picture gets brighter, which is why it is a favorite for dark-room monitors. White OLED answers back with darker blacks in a bright room and a tougher coating. The better pick depends on your room more than on any single number.