Why Do Some Displays Use Phosphor Compounds?

Phosphor compounds are commonly found in displays. Many computer monitors, TVs, smart devices and other displays feature phosphor compounds.

Phosphor compounds, of course, come from phosphate rocks. A study conducted by the United States Geological Survey found that there are roughly 71 tons of phosphate on Earth. Companies extract and process these rocks for use in various applications, including displays. From old display technologies like cathode-ray tube (CRT) to new display technologies like organic light-emitting diode (OLED), many displays feature phosphor compounds.

Electroluminescence

The reason some displays use phosphor compounds is electroluminescence. Phosphor compounds are electroluminescent. In other words, they illuminate when exposed to an electrical current.

All displays must produce light. Without light, you won’t be able to see the images on a display. Displays contain pixels that, when illuminated, result in visible images. While some displays use a separate lighting system, others use phosphor compounds.

Phosphor Compounds vs Backlighting

Most displays use either phosphor compounds or backlighting to illuminate their pixels. Phosphor compounds are electroluminescent, so they’ll illuminate automatically when exposed to an electrical current. In CRT displays, for instance, electrons are blasted at phosphor compounds, which causes them to illuminate.

If a display doesn’t use phosphor compounds, it will likely feature backlighting. Backlighting is a separate lighting system. Light-emitting diodes (LEDs), for instance, are commonly used as backlighting. Displays that don’t use phosphor compounds may feature a set of LEDs behind the pixel layer. The LEDs will produce light that illuminates the pixels from behind.

Problems With Phosphor Compounds

While phosphor compounds can illuminate automatically when exposed to electrical current, they have some disadvantages. Displays that use phosphor compounds are susceptible to screen burn-in. Screen burn-in is a visual phenomenon in which an image becomes permanently imprinted onto a display. If a display shows the same image for an extended period, it may develop screen burn-in with that image.

Only displays that use phosphor compounds are susceptible to screen burn-in. Displays that use backlighting are protected from this phenomenon. They may experience mage persistence, but they won’t experience screen burn-in.

Phosphor compounds also lack the consistency of backlighting. Backlighting will produce consistent light that eliminates the potential for bright and dark spots. Phosphor compounds, on the other hand, may lack this consistency. Some of the phosphor compounds may produce brighter light than others. As a result, the display will suffer from uneven or inconsistent lighting