How does a QLED panel work?

Samsung has been offering QLED TVs, which were previously known as SUHD TVs, for sale since 2017. These TVs, which are considered premium products, utilize QLED panels. While QLED may sound similar to OLED, it is actually an advanced version of LCD technology. In this article, we will delve into the inner workings of QLED TVs and discuss the benefits they offer compared to traditional LCD televisions.

QLED TVs employ LCD panels similar to those used in traditional displays. However, they are presented with an added feature. The added feature is based on a layer of quantum dots. This layer enhances the color volume and overall image quality.

In traditional LCD displays, a blue backlight and yellow phosphorous layer are combined to generate a white backlight. This white light is then filtered. After filtration through color filters, it produces red, green, and blue light. These colors can then be mixed to create any desired color. However, the white light produced in this way is not completely white i.e., it is not pure. As a result, the red, green, and blue colors produced are not pure either.

QLED technology addresses the issue of impure colors by using a blue backlight. The blue backlight is added in combination with a thin layer of quantum dots. This layer is composed of millions of red and green quantum dots, also known as QDCC (Quantum Dot Color Converters). These dots absorb energy from the backlight to produce a monochromatic color, a single pure color. The size of the quantum dots is measured in nanometers, and different sizes have different colors. For instance, a 2nm quantum dot generates pure blue light when energized by the backlight, a 3nm quantum dot produces pure green light, and a 4nm quantum dot generates pure yellow light.

When the blue light is reflected through these quantum dots, it can produce pure red, green, and blue colors. One thing to notice here is that the blue backlight is passed through directly. It does not require passing through blue quantum dots. In this way, power is conserved, and luminance is improved. The result is pure red, green, and blue colors, which when combined can create purer desired colors in contrast to traditional LCDs. This is why Samsung claims its QLED TVs can produce 100% color volume and over a billion colors.